brake lights stay on so how do i remove and replace brake light switch

Unplug switch. Then look to make sure the brake lights went out , if not you have a wiring problem elsewhere. Then either 12 or 14 mm. wrench loosen the lock nut and unscrew the switch from the bracket . Installation is reverse of removal ....but be sure it's adjusted properly so the brake lights go off (pedal pushing switch plunger in). Good luck.