can u provide a diagram on how to thread the rubber belts for the tape decks

Ed,

If you mean replacing the belt without taking the mechanism apart, you probably can't. In general you'd have to take the mechanism out of the chassis, and usually have to remove at least the capstan flywheel thrust bearing. Most belts don't thread in.

While I don't know your specific model, most cassette transports have the belts installed during assembly. You'll have to look at the service manual for your model to be sure. It often can take a couple of hours, even if you done this many times before.

Regards, Tim