Left fan stopped working and I didn't want to replace the entire machine quite yet (or bring it to a repair shop).
Went very well. Only took about 30 minutes.
Much easier than I thought. Just keep the screws organized when you take things apart. My only complaint is that the tip on the philips screwdriver broke off shortly before I was finished (had to use an eyeglass screwdriver to get some of the screws back in place). $60 and 30 minutes is much nicer than about $150 and 3-4 days (what my local, Apple-recommended repairer was going to charge).