R53 Serpentine Belt
… Definitely not a solo DIY.
Why?
Because, holding the tensioner with the tensioner tool and trying to stick an allen key wrench into the socket at the same time is impossible.
Edit: Drove Cherise around a day after installing, and I must say the car is responsive. My old belt must have loosened up over the past 4 years but not enough that it would noticeably slip.
Oh and I also had a MASTER technician check out my ride and awesomely enough, Cherise is doing well on her bushings and what not even at the 4 year mark. The only thing that would become a problem in the next 5k miles or so is my motor mount, but that’s because I never leave 2nd gear in rush hour traffic.
Edit: Here is the PDF file how-to for the DIY belt change. I take no credit or liability for someone doing their own DIY. I’m just hosting the file.