1. Locate the brake light switch. The brake light switch is located on the brake pedal assembly. It is a small, round, black switch with two wires connected to it.
2. Disconnect the electrical connectors. Before you can remove the switch, you will need to disconnect the electrical connectors. To do this, simply press down on the tabs on the connectors and pull them apart.
3. Unscrew the switch from the retaining nut. Use a wrench to loosen the retaining nut that holds the switch in place. Be careful not to drop the nut.
4. Remove the switch. Once the retaining nut is loose, you can remove the switch from the brake pedal assembly.
5. Install the new switch. Place the new switch into the brake pedal assembly and thread the retaining nut back on. Tighten the nut until it is snug.
6. Reconnect the electrical connectors. Plug the electrical connectors back into the switch. Make sure that the connectors are securely seated.
7. Test the brake lights. Press down on the brake pedal and check that the brake lights are working properly.
That is how you replace the brake light switch on a 1993 Buick Roadmaster.
