My 2 year old pulled some key caps off the keyboard, and then my 4 year old spit lemonade all over my macbook.
It went fairly well. I put most of the screws in bowls or baggies labelled with the step number from the repair guide. This helped find the right screws when putting it back together.
Separate the different sized screws. Some in the same step differ by less than a mm. Buy a good phillips screw driver; the iFixit torx and tri-wing drivers gave me no problems, but the Canadian Tire phillips drivers gave me a lot of trouble. I was worried I was going to have to drill out a few screws and find replacements.
TR8 Torx Security Screwdriver
Tri-point Y1 Screwdriver
TR6 Torx Security Screwdriver
MacBook Unibody (A1342) Upper Case