When timer knob pulled out the dryer would not start.

Shut off breaker to dryer. Used a small standard flat tip screw driver to remove plastic cover on timer knob. The ring and knob then pulled straight off. Next, removed three torx-head screws on the top of face plate, lifted face plate at a curved angle to gain access to the timer module. Slid timer module off the mount unpluged timer module, replaced timer module and plugger in electrical connector. Re-installed face plate, attached torx-head screws, installed knob and retainer. Works like a champ !! Easy repair Job !!!