I havent had to replace the belt on my 450i yet but have on my 4 wheelers. On those I was able to manually manipulate the clutch ( open the sheaves) to allow enough play to work the belt over and get it off, same putting the new one on, but cant say for sure on the 450i. Manual says to remove one clutch, but then so did my 4 wheeler manual....might help to have an extra pair of hands to open the clutch while you work the belt over the sheave edge. If you have to remove a clutch, it shouldnt be that hard. One of them will come off the shaft in one piece, not sure which one though...