just replaced belt and working ok, now i know how an olympian feels after winning gold
take lid off,,,, undo all of front (leave wires attached),,,, undo sides (take screws out of left and right sides approx 10 screws at back),,,,place belt round drum near mark left by old one,,,, lean on front of drum to lower drum to the motor spindle,,,,,,pushing hard down on drum will bend the drum on the inside as it touches the motor housing (don't worry it bends back),,,,,,,you should then have the drum close enough to the spindle to lever the belt over by hand,,,,,pull drum back up,,,,,rotate by hand to let the belt self align,,,,shouldn't come off spindle if you put it on with 3-4 grooves spare,,,,,, do back up (10 screws),,,,put front back on and pull drum onto the lip on the front of the frame,,,,may be a bit noisier until belt beds itself in,,,,,,
hope this helps, if not got an engineer to do it last time and it cost me £48 (belt was £13 so £35 labour), watch him like a hawk and then you know for next time
Craig,,,Lincs, January 2009