To take the switch out and install it, you need to loosen the wiring at the back of the switch. Then loosen the lock nut which holds the switch on the bracket, take off the lock nut, and the switch. Install the new switch, and screw it together using the lock nut but not too tight. Install the brake light switch in such a manner that there is a distance of 0.6-1.0mm between the outer case of the switch and the pedal such that when the pedal is in the off position, the switch tab or prong slides against the pedal and the switch tab releases the switch and closes, and when the pedal moves away, the switch tab slides back in place reopening the switch. Switch the switch and tighten the lock nut and reconnect the wiring. To test the operation, switch the ignition key to ON without starting the engine, and have someone watch the brake lights as you push the brake pedal a little, the lights should come on as the pedal enters the range of free travel. Tilter the switch as necessary to provide the appropriate response of the lights, keeping in mind that the little amount of free travel in the pedal should not lead to the activation of the brake lights, since improper settings would result in flickering of the lights caused by the vibration of the pedal on the bumps on the road.