Brake switch has gone bad correct way to install a new one.

Disconnect the connector and remove the adjuster nut while noting approximately where it sits on the threads of the switch (This will give you a good starting point for the new switch). Remove the switch from the bracket and push the new one through. Set it with the nut so that the pedal pushes the center part of the switch in completely when the pedal is released but isn't putting any 'extra' pressure on the switch. I usually set them to where you can hear an audible click from the switch at the same point where you push the pedal down to take up the play in the pedal (just before it starts pushing on the pushrod that goes into the master cylinder).