The fan on my MacBook Core Duo stopped working and the laptop ran very hot such that I had to always use and external cooling pad.
The replacement was a simple project. The instructions were, as always, very easy to follow.
It is essential to have a means of setting aside the screws that are removed in each step in such a way that you can easily retrieve the correct screws when reassembling the computer. Any means of isolating the screws removed at each step and labeling them accordingly will work.
Also, I found it virtually impossible to remove the old fan without tearing the felt tape (Step 20). It would be very helpful if iFixit were to suggest an appropriate alternative to the felt tape or sell replacement tape. It seemed to me that the only purpose of the tape is to seal the junction between the fan and the vent. After removing the residual felt tape fragments, I used Black electrical tape as a seal, but I have no idea if that will be a satisfactory alternative. Guidance in the instructions would be good.