I read a thread a few days back that someone was having a bit of trouble removing the headlight switch. Now I can't find the post. Here's a couple of pics that make it easy to understand. At least this is how it worked on my '50 AD.
First release the stem by pushing the button on the side (1st pic). Then simply unscrew the faceplate which mounts the switch thru the dash (2nd pic).
Ok i tried to get mine outis there a trick to getting the knob out i pushed in the button as hard as i could and couldnt get the knob out i pulled twisted turned all of the above???