Do not try and take the back cover off!
Instead. Undo 2 screws that hold top down which are at the top on the back of machine; push top towards the rear to release - you might have to jiggle the top from side to side to slide it about a half inch.
Next unclip the cover at bottom front of the machine by inserting a flat head screwdriver into the small slots under the plastic plate. Wedge plastic prods go into this-have to lay dryer on its back to do this.
Then undo the screws along the bottom that were under the plastic plate.
Set the dryer back on its feet and undo the two clips holding the switch panel and pull upwards. This shows 2 screws to release the front panel. Be careful as these are connected by wire so don't pull too hard. You can now access the drive belt and motor.
Phil
August 2009