You need to remove the bottom cover I think there are 7 screws, next, take the brushroll out. it might stick a little because of dirt, but there is nothing holding it in once you remove cover. If the belt is still attached slide the brushroll through it to remove it. It will be a tight fit, but it can be done. Next, take a loop of the belt, back in the slot in the housing there is gear on the motor and you need to hook the belt over it (you my need a flashlight to see it). (also, ignore the silver bearing, it doesn't go around that) now squeeze the brushroll through the other end of the belt until it's on the geared part. place the brushroll back in the housing. and reattach bottom cover. I hope this was helpful.
DRGenack
August 2008