From Way of Shinsei 

Adapting monks for 2nd Edition is surprisingly easy, since many kiho operate off of Rings rather than skills, and a good number of them already imposed bonuses or penalties to rolls rather than die increases/reductions. As a general rule, take anything that causes a loss from the die pool and replace it with a +5 TN Penalty/dice lost. Anything that allows a character to ignore dice penalties similarly allows you to ignore +5 per die formerly ignored. All skill roll TN's are lowered by 5. Ring and Raw Trait TN's (which most kiho run off of) are unchanged. 

Rules for obtaining and purchasing Kiho remain unchanged, as do the general kiho types. All Mastery Levels remain unchanged, as do the rules for determining Mastery. In fact, the only thing that changed in monk character creation is the following: 

Mushin Kiho - Characters may make additional (not free) Raises on Atemi attacks equal to 1/2 their Atemi skill (round up) rather than their Atemi Skill. 

Monks receive 30 character points at creation. 

As for individual kiho, here's what has changed. 

Grasp the Earth Dragon - All TN penalties (including those caused by wounds) are decreased by the monk's Rank X 5. This replaces the kiho's previous ability. 

Musubi - The monk gains a bonus to his roll equal to the amount by which his attacker missed. 

Dance of the Flames - This kiho is the only one that needs to be *entirely* reworked for 2nd Edition. My suggestion is as follows:
            The monk gains an additional number of attack dice equal to his Rank, and then divides that pool as equally as he can among all attackers. This kiho may not be used against less than two attackers at a time. Kept dice are no longer affected by this kiho. Void can be spent on individual attacks as normal.
            For example: A Rank 3 monk with 5 Bojutsu and 3 Agility is being attacked by 4 bandits. He decides to use dance of the Flames. This allows him to attack each bandit in range, rolling 2k3 dice against each one. Alternately, he could choose to attack only three, rolling 3k3 dice against two of them and 2k3 dice against a bandit of his choice. Or, he could attack two of them, rolling 4k3 against each of them. If he chose to only attack one bandit, he would not be able to use this kiho and would roll 5k3 normally. 

Stain Upon the Soul - The dice penalties imposed by this kiho are changed to a TN penalty equal to the monk's Air + Rank. The duration remains the same. Multiple uses are still cumulative. 

Self, No Self - The Meditation TN of this kiho is now 15. Yes, this is better than the normal Meditation TN (which is unchanged) but this is a more efficient form of meditation. 

Touch the Void Dragon - The TN of the Perception + Shintao roll is now 10, not 15.

From Way of the Dragon 

Ise Zumi Conversions 

The TN for "shutting off" a tattoo has been reduced from 15 to 10. 

Tattoos 

Bamboo - While using the power of this tattoo, the ise zumi's Stamina is increased by an amount equal to his School Rank, and Stamina-related skill rolls roll and keep extra dice equal to his School Rank. This lasts a number of rounds equal to the Ise Zumi's School Rank. The cost of using this tattoo is unchanged. 

Bat - While using the power of this tattoo, the ise zumi's Reflexes are increased by an amount equal to his School Rank, and Reflexes-related skill rolls roll and keep extra dice equal to his School Rank. This lasts a number of rounds equal to the Ise Zumi's School Rank. The tattoo still does not affect TN to be Hit. The cost of using this tattoo is unchanged. 

Bellflower - The Ise Zumi may substitute his Void for any Trait or Skill for a number of Rounds equal to his Rank. He may not substitute his Void for skills in which he is unskilled. 

Butterfly - While using the power of this tattoo, the ise zumi's Awareness is increased by an amount equal to his School Rank, and Awareness-related skill rolls roll and keep extra dice equal to his School Rank. This lasts a number of rounds equal to the Ise Zumi's School Rank. (The duration of this tattoo is, in fact, much shorter now due to the increased effect of Awareness on combat.) The cost of using this tattoo is unchanged. 

Centipede - This tattoo increases the ise zumi's movement from Water X 5 to Water X 100 for up to twenty four hours. While moving in such a manner, the Ise Zumi's TN to be hit is increased by his Reflexes + his School Rank. Once it is deactivated, the ise zumi is effectively Out (the Pine tattoo cannot negate this), and must rest for the amount of time he ran, multiplied by (6 minus his School Rank). 

Crab - The benefit of this tattoo remains the same. The cost, however has changed. While using this tattoo, the ise zumi receives a +5 TN penalty to all skill rolls involving Reflexes. 

Crow Tattoo - The benefit of this tattoo is the same, but the cost is different. Any Shadowlands creature making a Perception check against the ise zumi gains a bonus to his roll equal to the ise zumi's Rank X 5. 

Lion - The ise zumi may roll extra dice equal to his Rank on all Bugei Skills. This does not affect whether or not he is considered unskilled with a particular Bugei Skill. 

Monkey - The ise zumi may roll extra dice equal to his Rank on Stealth, Sleight of Hand, and other skills requiring subtlety. When making any climbing or leaping actions, he also gains this bonus. The cost for this tattoo is unchanged. 

Mountain - The benefits of this tattoo are unchanged, but the ise zumi may also roll additional dice equal to his School Rank on all Stamina and Willpower skill rolls. The cost of this tattoo is unchanged. 

Pine - The tattoo now cancels penalties due to Wounds as follows:

            School Rank 1 - Ignore up to +5
            School Rank 2 - Ignore up to +10
            School Rank 3 - Ignore up to +15
            School Rank 4 - Ignore up to +20
            School Rank 5 - Ignore Down and Out
            The cost of this tattoo is unchanged.

Scorpion - When other make a roll against the ise zumi (whether with an attack roll or a social skill) they cannot keep more dice than their lowest Trait. The cost effectively Raises the TN for any social skill performed by the ise zumi by 10, 40 if he is actively trying to convince someone else that he is telling the truth. 

Tortoise - The ise zumi may substitute his School Rank X 2 for any Skill a number of times per day equal to his School Rank. This benefit lasts for an hour per Rank of the ise zumi. The cost of this tattoo is unchanged. 

White Mask - This tattoo instills a penalty of +40 on all attempts to read the ise zumi's emotions or thoughts, whether by courtly skills or magic. The ise zumi may never keep more than one die on any social rolls involving Awareness.

From Way of the Phoenix

Henshin 2E Adjustments

Rank Effects

As ranks are assigned, the PC gains the ability to add or subtract five times their rank to his own die roll, or twice his rank to the die roll of another character (PC or NPC). Even though the Henshin may progress into a higher School Rank, the Elements he has already assigned will never provide more than the value of the School ranks at which they were originally learned. These abilities require no roll, and the duration of the effect is equal to the Henshin's current school rank. The use of a mystery is considered a combat action, and is declared in place of attack, full attack, or full defense. These bonuses and penalties apply only when the target is making a skill or Trait roll which relies upon the appropriate elemental Ring. Mysteries are ineffective against targets other than yourself if the target's elemental Ring to be effected is higher than your own.

For example: Asako Kaushen is currently School Rank 3, and has chosen the following Rank/Element assignment - Rank One Air, Rank Two Earth, Rank Three Fire. He may do the following:

Add or subtract 5 from his own Reflexes, Awareness, or Air rolls for three rounds, or add or subtract 2 from another's Reflexes, Awareness, or Air rolls for three rounds.

Add or subtract 10 from his own Stamina, Willpower, or Earth rolls for three rounds, or add or subtract 4 from another's Stamina, Willpower, or Earth rolls for three rounds.

Add or subtract 15 from his own Agility, Intelligence, or Fire rolls for three rounds, or add or subtract 6 from another's Agility, Intelligence, or Fire rolls for three rounds.

Riddles

Activating a riddle requires the henshin to roll the appropriate Ring vs. TN = five times the rank at which the riddle was learned. Riddles are instantaneous when applied to yourself, and are a single action when applied to another. Should the roll for using a riddle fail, it has the opposite effect (inflicting extra wounds rather than negating them, imposing a penalty rather than a bonus, and vice versa).

Riddle of Earth

The henshin may reduce the number of Wounds taken by an attack by (Chosen School Rank for Earth + Earth). He may heal the same amount of wounds taken by another by touching them.

Riddle of Water

The henshin may add his (Chosen School Rank for Water + Water) to all Perception related skill rolls and raw perception checks. He may impose an equal penalty to the Perception rolls of anyone attempting to observe him when he wishes to remain hidden.

Riddle of Fire

The henshin may add his (Chosen School Rank for Fire + Fire) to all hand-to-hand combat skill rolls, and to his initiative when using hand-to-hand combat.

Riddle of Air

The henshin may add his (Chosen School Rank for Air + Air) to all skills involving social interaction. He may reduce the sincerity skill roll of anyone attempting to lie to him by an equal amount.

All other aspects of the henshin remain unchanged.

Also From Way of the Phoenix

Isawa Ishiken - Ishiken are considered to have an Affinity for Void, and no Deficiency. See the Game Master's Guide (page 237) for Mastery Levels of Void spells.

From Way of the Lion

Matsu Bushi Rank 3 - The Matsu Bushi may now add her Honor X 2 to all Initiative rolls.

Also From Way of the Lion

Kitsu Sodan-Senzo School

Bloodlines Advantage (5 points, WotL pg 48) - Remains as is.

Half-Blood Kitsu Ancestry (3 pts, WotL pg 52) - Remains as is.  Can be purchased by Kitsu shugenja to gain the spell "Sense Ancestor."

Full-Blood Kitsu Ancestry (5 pts, WotL pg 53) - Done away with completely.  The ability conferred by this advantage is gained by attending the Kitsu Sodan-Senzo school.

Sensing Ancestors - Remains as is.

Communing with Ancestors - Remains as is.

Summoning Ancestors - The sodan-senzo rolls Intelligence, keeping School Rank to summon ancestors.  The TN is equal to the character point cost of the ancestor being summoned.  The sodan-senzo may only summon ancestors whose character point cost is equal to or less than twice their School Rank + Honor.

Recommendations

I recommend changing the sodan-senzo starting package as listed below. 

Benefit: +1 Willpower

Beginning Honor: 3, plus 5 boxes

Skills: Calligraphy, Etiquette, Heraldry, History, Lore: Ancestors, Meditation, and any one High or Bugei skill.

Spells: Sense Ancestor, Commune Ancestor, Summon Ancestor, any 2 Air spells, and 1 Water spell.  Kitsu sodan-senzo have an Affinity for all Ancestor spells and a Deficiency for Earth and Fire spells.

From Way of the Minor Clans

Sparrow Rank 1 - At the beginning of the round, a Sparrow may voluntarily lower his own initiative to raise his TN to be hit by half that amount (round up). His TN may not be raised by an amount greater than twice his Reflexes, and he may not use this technique while making a Full Attack. (The free Lore skill ability is unchanged.)

Sparrow Rank 2 - The Sparrow's TN to be Hit is increased by +5 against any human attacker with lower Honor.

From Way of the Crab

Kuni Witch Hunter School

Rank One: Unchanged

Rank Two: TN to detect Shadowlands creatures is reduced to 10, 15 if they are adept at hiding their nature.

Rank 3: The Witch Hunter gains a bonus to his attack roll equal to his opponents Shadowlands Taint X 5. Against native Shadowlands creatures, they gain the following bonuses:

Goblins, Hanemuri, lesser Oni (minor creatures)                        +5

Pennaggolans, Gaki (moderately powerful creatures)                        +10

Ogres, Trolls, Bog Hags (very powerful creatures)                        +15

Oni (very powerful creatures)            +15 or more (GM's Discretion)

Rank 4: The TN to make another person resistant to maho for one round is reduced to 20.

Rank 5: Unchanged

Note: In second edition, Kuni Witch Hunters may continue their schooling at the Kuni Shugenja School. See Way of Shadowlands for details.