It is difficult to do, but possible with some good tools and a strong pair of hands. To change the belt, lay the machine on it's front, undo the 2 screws at the top of the back on plastic lugs, undo heater housing and lean to one side, undo 3 nuts on motor fan and remove, undo 2 hose gasket screws and remove gasket, then remove all screws down both sides of the back of the machine, 2 on the bottom edge. Then, using a long strong screwdriver, separate the bottom from the back panel, it slots into the base, lift the top off, splay the sides of the machine out and lift off the back cover, carefully as there are wires connected and leave to one side. Remove the broken belt which will be loose inside, put the new belt on the motor spindle first then stretch the belt around the drum. It will look like it will never fit, but it does, it just needs to be stretched, a lot! If you wedge the belt on with strong screwdrivers, which will help you pull the belt on. Once the belt is around the drum, you need to ensure it is centred on the marks on the drum. Putting it back together is an exact reversal of what you've just done. Before refitting everything, it would be worthwhile checking the drum shaft is ok. This is a fitting in the centre of the back of the drum that holds it in place. When the belt went on our machine, the drum banged off centre and sheared the shaft off, bit of a bad design if you ask me! The shaft kit is also available from most machine spares shops, ours cost £15 and the belt was £9.50. The shaft is not too bad to fit, once you have the machine apart but you'll need a rivet gun as the shaft bush sits inside a plate that is riveted onto the back plate.
Hope this helps and good luck!
Sharon B, December 2007