Sorry for the (very) late reply. If you still need the info:
You need to remove the bottom of the machine, and remove the old belt, which is the simple part. The difficult part is getting the new belt on. Inno was extremely unhelpful when I called after trying for hours to get it changed out. Here's the trick, and I couldn't believe how simple it was:
Thread the belt on the metal piece towards the back of the machine, then take a very strong twist tie, and tie the belt securely to the back wheel (closest to the metal piece). Thread the other end of the belt over the front wheel, and spin. As long as your tie stays secure, the belt will slip right on. Remove the tie, and voila!