Here's how I did it...
First and foremost make sure you have the correct belt. There seem to be 3 sizes of belt for the Zanussi TC470. I telephoned the serial number of my machine to the help desk to ensure I bought the correct one.
Isolate machine from the mains (pull the plug out!). Remove water tank.
Remove 2 screws from under back of lid, slide lid back and lift lid off.
Remove single screw from white cover at bottom rear of machine. The right hand side of the white cover is a push fit into the rear panel and is detached by lifting the lugs over the edge of the panel. Remove white cover. Remove figure-of-eight fan belt.
Remove screws from around the edge of the rear panel. Get the missus to help support the front of the drum. Lift the drum and rear panel back from the front panel a few centimetres until there is a small gap at the front.
With the assistant holding the front of the drum, place the new belt around the drum at the door end (front) of the drum and down through the small gap you've just created.
Take this opportunity to remove fluff from the circular slot in the front panel which the drum fits into.
Slide the rear panel with drum forward, locating the front of the drum back into the slot.
Replace the screws holding the rear panel to the frame, checking that the drum revolves freely before finally tightening them.
You'll find that there's a trace of a track on the rear of the drum left by the previous belt. Manipulate the new belt back over this track, making sure that the ribbed side of the belt is in contact with the drum. Place a couple of bits of duct tape over the belt to hold it in position.
Before tipping the machine forward onto its front, put down some protection onto the floor to avoid damaging the control knob. Also be aware that some residual water will escape from the machine onto the floor. Tip the machine onto its front.
With the assistant at the lid end of the machine and yourself at the bottom, revolve the drum. As the drum goes round, the assistant should place additional bits of tape over the belt at the top and you should remove them at the bottom until you're satisfied that the belt is not twisted at any point.
Pull the belt over the shaft of the motor.
You'll find that you can lift the motor against some springs which are attached to its mountings. Lift the motor against the pull of the springs as high as you can and then pull the belt over the left hand side of the small tensioning pulley wheel so that it's the non ribbed side of the belt which is in contact with this pulley wheel.
Check that the belt is correctly located on the shaft of the motor and turn the drum a few times to make sure it revolves smoothly with the belt correctly in place.
Replace figure-of-eight fan belt and white cover. Lift machine back onto its feet and replace lid.
Photos showing how I fitted the belt around the motor shaft and tensioner is shown on
https://skydrive.live.com/?cid=cff8b156bb421f53&Bsrc=EMSHOO&Bpub=SN.Notifications&id=CFF8B156BB421F53%217323&sff=1
kipper
October 2011