These dryers just keep on going don't they?
You may be able to do this with the dryer face down and supported on the corners, but this is how I do it.
With the dryer at a comfortable height and in normal orientation , insert the drum with the belt around it ( belt smooth side out ) inwards and push it towards the front It should be freely rotating (you support the back ) align the belt with the motor pully and hook it over the shaft, you will have to prise apart the two spring loaded tension pulleys to make an omega type route.
Make sure the belt is not skewed to the drum rotation ,if it is, the belt will slip off the when it first runs.
You can check by carefully rotating the drum, adjusting the belt on the drum to stay aligned.
The drum should stay supported like this if you don't knock it around too much
Hold the back panel close to the dryer and clip the wires from the temp sensor back the way they were originally.
Push the back panel in place taking care to align with the back of the drum, ( fan housing and drum will be a snug fit ).
You may need to lift the back panel slightly 2-3cm ( drum will move as well ) to lock the bottom panel cutouts in when it eventually aligns to the screw holes.
Before you tighten all the screws test the rotation by gently turning the drum from the inside.
greg
March 2008