The fan in my 2006 MacBook was really loud and ran at 4500 rpm (now, 1500 rpm again).
Easy. A lot of screws but easy overall. Really you do not have to have any special tools and the instructions here were great.
Have a small, clear, plastic container ready. I had one large enough for me to set the screw up in a formation that resembled the laptop layout. But, you'll also remember, because the process is not that long.