If I could just add a few bits that helped me.
Remove the white plastic bit at the bottom that covers the small belt (looks a bit like a car fan belt). Two screws I think, then remove the belt.
Lid off, then onto the back plate.
You only need remove the outer bolts on the back and the drum comes away with the back plate. Move the whole back plate back slightly so that the drum clears the front , dont pull too hard, or too far, you don't need to. Watch for any wires, I seem to remember a few. There is slack so don't panic. Clear out the fluff from the front where the drum sits/rotates, there's a surprising amount in there. I found this easier with the front loading door open and hooked my finger inside.
Loop the belt over the front of the drum and slide it to the back.
Right, now the bit that threw me. Everyone said move the motor to the left (anticlockwise) against the spring tension. Mine however was tensioning to the right (clockwise). When I pushed it anticlockwise it just stopped against the spring which was in a vertical position to the left of the motor. Then I read a thread that said their spring had gone into the wrong position probably when the tension was lost when the belt snapped. With this in mind I pushed the motor to the left and eventually the spring (with a fair clang) popped under the motor and was now laying almost horizontal beneath the motor. This now changed the tension to anti clockwise. The correct belt routing is then under the drum from the left, over the top and clockwise round the tensioner, then anti clockwise round the groved pulley and up to the right hand side of the drum. Hope this helps, many thanks to all those who have posted here and on other sites for their excellent help. By the way, N. Kelly is spot on about the cuts, prepare to get a few.
Paulie, April 2007