==ALWAYS BACK UP YOUR FILES BEFORE INSTALLING A MOD==
How to install:

Go to the Tactics Ogre Reborn directory on your system. It is usually under Steam/Games/Tactics Ogre Reborn. Go to the Data folder
Make a backup copy of Filetable.bin. Go to Battle (in the data folder) and make a copy of battle_data_release.dat. 
This should back up the original game files and make it easy to revert to them by replacing the modded files with them at any time.

Go to the MVCMod folder.
Copy the filetable.bin file, and paste it in Tactics Ogre Reborn/Data. Copy the battle_data_release from the mod folder and paste
it in Tactics Ogre Reborn/Data/battle. 
This should succesfully install the mod. 
Be aware that most class changes will require the unit to level up or change classes at least once for the game to reflect the changes.

Changes that MVCMod entails:
Dark Priest get Whips, Knives, Swords
Berserkers can use 2h swords
Dragoons get Double Shot, +1 movement, Dex and vit growth slightly raised . Slayer skill costs reduced by 10 mp.
Warlocks/Witches proficent with relic swords and daggers
The Phoreana sisters can change their elements as Shamans. Shamans innately levitate.
Apocrypha 1 and 2 have their area of effect increased by 1 respectively
Elemental Missile spells (except for light, earth, and dark) of ranks 2, 3, and 4 have a small chance (10, 20, 30% respectively) of inflicting a debuff. Earth has a higher chance of knockback. (Fire can inflict weaken, water can inflict breach, lightning can inflict stun, ice can inflict slow, wind can inflict leaden)
Rogues recruitable. Rogues get Pincer Attack, Paralysis Blade, Quick Draw, Back Attack.
Ranger gets Intimidate
Back Attack buffs the user with Dodge
Shields (+1 and Relics) Get a free cast of a class skill if no use effect is present
Lightning Gauntlets get a free cast of Paralytic Wave,  Fire Gauntlets get a free cast of Petriburst
MP bonus from Chokers doubled
Blacksteel/Lacquersteel Blade gets Breach on hit
Baldur Golems can cast spells and have a little more intelligence. Stone golems have higher defense gains, iron golems have higher attack scaling.