In an ongoing video tutorial series from Macht Schnell, this post will outline the steps needed for installation of the the Macht Schnell Performance Underdrive pulleys on the 2008+ BMW M3:
e9x M3 S65 Performance Underdrive Pulley Set (belts included)
14mm Wrench (open end)
1-3" drive extension
1"-3" 3/8" Drive extension (optional)
Time needed for installation is approximately 60-90 minutes.