Yes, it might be hard etc. but you can, just make a char that has the same exact kit, save exit and look at the Kit: Set Value with ShadowKeeper under the Characteristics tab, copy it and then insert it to the same spot on your already created char.Silly question: Is it possible to put a mod kit on a PC with ShadowKeeper.
Now if you want all the new abilities from level 0, you need to give him 1 hit point(base, and current), set all the saving throws to 20, experience can stay, level 0, Thaco to 20, base AC 10 etc. and save.
Load the game, level him up, and go and take the 1 excess hit point away, with SK. Easy!!!