Try holding the rear knob dial indicator and twisting the front top knob in reverse.......once you remove the outer knob you'll probably notice 2 screws under the outer dial that you have to remove to pop it out......try a small flathead screwdriver or putty knife to release the connections to the timer

I received a timer replacement, P/N 33002855 today. I attempted to twist the front top knob in reverse while holding the knob dial indicator as directed. The knob did in fact rotate counterclockwise as suggested. However, the knob did not release from the shaft. It moved out approx. 1/4" but did not release. It felt as if it was spring loaded and not releasing from the shaft.
I contacted the repair forum via telephone. The gentleman confirmed what I had done but was unable to provide any further procedure to release the spring loaded knob. I could not see or locate 2 screws under the outer dial probably because the knob would not release. Any further suggestions?