A friend of mine spilled Greek Yogurt all over her A1342 Macbook Pro. At first only the N key didn't work, but over the course of a week many more keys started sticking and stopped working. Apple wanted to charge her $800, I told her less than fifty.
It all went super smoothly, transplanting the innards from one unibody to the next. I had a tough time figuring out how to get the display disconnected from the motherboard. Based on all the previous connectors I assumed that you pulled up on the cable. Well, that was wrong, you're supposed to pull parallel to the motherboard. That was pretty scary. And then putting it all back together I forgot where the long screw (about an inch tall) went. It took about five minutes, but I found the right hole for it without damaging anything.
I used electrical tape to hold down the screws, and that worked pretty well. I'd say have the electrical tape on a piece of paper or something (because I didn't buy the magnetic white board from ifixit) so you can write hints next to the screws so you don't forget.