if you mean the switch under the knob, you can open up, drill, the switch and clean up and use it again, uless the copper parts are burned out.
to get to the switch, most likely have to unscrew all the screws holding the top and the bottom together, most likely the screws will be on the top, by the gas burner on each burner. and may need to check the sides for additional screws .
if you go step by step , its pretty easy. maybe you should look up on you tube for demo.
there is a problem with either the elements or the controls,i doubt it is the elements as its unlikely that all of them are faulty at once.the control knobs or control panel is more likely the problem.
Throw the burners in a large garbage bag and spray it with easy off oven cleaner. Seal the bag for a day and then rinse everything off. Clean the aluminum parts with a nice wire brush from the hardware store.