Well my left fan startet to make a grinding sound that just gon on my nerves. As we all know the MBPs are all really quiet (at least as long as the fan isn't running full speed), but mine was grinding away and driving me crazy so I looked for the cheapest and most trustworthy provider of this hardware and viola ifixit was there to help.
Well I've replaced my HD and repaired a dent in my right speaker grill, so I already knew how to take my MBP apart (if I remember correctly the first time I did it though, it was using a How-To from ifixit). My main problem was the fact that I didn't have the right tools to remove the Torx screws that were holding the fan in. So I ended up taking a small strait screwdriver and a hammer to really get it into the screw. With a racing pulse I gate the screwdrive a few good taps, tried it for grip and it fortunately worked.
Now everything is back to how it should be and I am happy.
If you're not a total klutz, then trust yourself, you'd be surprised at what you may accomplish.