How to Change the Brake Light Switch on a BMW

1. Climb down into the drivers side foot well area and pull the cotter pin out from the retaining pin that connects the brake pedal to the brake booster assembly. Use a pair of pliers.
2. Slide the brake booster-to-brake pedal retaining pin out of the brake booster mounting bracket. This will disconnect the brake pedal from the brake booster.
3. Lift up on the brake pedal and unplug the electrical connector running to the brake light switch behind the brake pedal.
4. Unbolt the bolts holding the brake light switch to the firewall and pull the switch off the firewall.
5. Install the new switch. Installation is the reverse of removal. When replacing the retaining pin that connects the brake pedal to the brake booster, slide the cotter pin through the small hole in the end of the pin and bend the cotter pin back over the retaining pin. This will secure the retaining pin in place and prevent it from accidentally sliding out of the brake booster mounting bracket.