Old MBP right fan
20 - 30 minutes
My 7 year old MBP works great, first physical problem (besides battery life): right exhaust fan died. Screeching and 0rpm alternating.
Replaced with fan from ifixit, had no trouble. Have used ifixit guides before to install SSD. Great site, great resource, okay prices but unbeatable inventory.
There are parts dealers on amazon with lower prices, but many claim genuine oem that aren't. For this part the price difference was less than 10 bucks and on amazon the reviews are horrid. I'll stick with ifixit.