Pull the electric plug. With a nut driver and phillips screw driver remove two bolts and three screws on the rear access plate. Gently pull the knob from the front pannel and with the nut driver remove the two bolts under the knob. The timer is now loose from the drver. Match the wire plug codes on the old and new timers. Remove one wire at a time from the old timer with pliers and plug it onto the new timer on the same coded pin. Slide the timer back into the pannel and replace the two bolts that hold it. Replace the knob. Replace the three screws and two bolts holding the back pannel. Plug the electric cord back into the wall socket.
Checked all other electrical and mechanical operations and all seemed operational. Removed heating element from unit and checked with vom. It was ok. Reinstalled and began checking wiring with vom per the diagram in the control panel cover. Determined that the contacts for the heater in the timer unit had failed. (Open) temporarily shorted these points on the timer with a strap to make the dryer work. Wife is now happy. Two days later when the timer part arrived, installed and now all is operational. Good for another 10 years. Dick