I had the same problem on another make of machine. The answer, I found, was to gently prise off the belt from the projector, keeping it in one piece if possible (and don't cut it if you can help it). I took the belt to a shop where they sold those decorative elastic bands that girls and women use to tie up their hair. I found a packet of elastic ties approximating in size to the original belt (which I had with me) and with a bit of care I managed to successfuly fit one of these makeshift bands to the machine (the makeshift band was smooth all round with no trace of where it was joined - make sure of this if you should find one). If mine should wear out prematurely, I've still got a pack of such bands - about 10 I think - and I know where I can get more if need be. Good luck.
George Scoble (UK), April 2008