Has anyone here had to or have replaced either of the fans in the MBP? My left one has begun to make a grinding sound whenever I run to many programs at once or play/burn/rip any type of CD/DVD. (I am 100% positive it is the fan btw) Blew it out but no help there. Anyway, I ordered up the left fan on ifixit and plan to follow the guide from the site to replace it. Any idea on how difficult the process will be? Any tips?