Its not that hard to diagnose the problem guy.
Do like I said to isolate the problem. Once you figure that out ask the shops how much they charge. if its too much come back here and ask again.
I mean what the hell.. if it is the tranny and someone comes down to work on it he's not gonna finish it that day because your friend doesnt have a new one ready to be put in, plus who ever does it is goign to have to drive to where you are unless u have it towed.. Running around for parts is a pain the ass especially when your gonna get paid less than what a shop is and its gonna take longer..
And if your friend wants it fixed he'll be the one asking for help on here. Let him worry about his problem.