I wish more people would post up "how-to" posts. I usually take pics as I take things apart any ways, so here is my first "How To" post! HOW TO REPLACE THE DRIVE BELT ON A TORO PROLINE 21" (or Exmark metro 21"): 1. Remove black cover w/ two screws. 2. Inspect belt. (see this one is frayed) 3. Remove blade. 4. Remove crank sleeve and housing. The crank sleeves pulls straight out. The housing has 3 bolts. 5. Slide old belt off crank. Thread new belt in. It is very important to attach the belt to the tranny pulley BEFORE the crank pulley and BEFORE you re-assemble the cover on the bottom. 6. Put it all back together. Note the "Key" on the crank has to match the crank sleeve. Total time spent = .5 hour It is a 3 year old mower with about 1,000 hours on it.