The bezel nut that holds the switch into the dash won't come off without destroying the chrome disc that covers the lock tumbler. It's easy to remove the tumbler- - - - -IF- - - - -you have a key that fits. Otherwise, you're going to need to pick the lock so you can turn it away from the "off" position and expose the release pin that is accessible through the small hole in the chrome disc where the key is inserted. Once that lock pin is depressed, you can turn the lock tumbler further to disengage the tumbler from the switch. THEN the bezel nut can be removed.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!