replacing fet's in a bk9920

[tashpop]

i had one fet with a little burn on it, and i want to replace it. i've pulled the esc apart, but haven't gotten the numbers off the fets yet. where would one locate fets at, and also i notice even though the two boards appear to have the same sized fet's, they look like they have different numbers on them. i accidently pulled off two extra fet's getting the heat sink off, so i'll need a total of three. if anybody wants to save me some time searching, let me know which fet's the bk9920's use and where they are that would be great.

one more thing, how do you get that white poo off of everything, and what is it so i can put it back.