Disconnect the negative one of the battery. For E30 models, take off the lower left dashboard trim just under the light switch. Screw out the light-switch button. Unplug by and pull-off switch. Install knob, connector and switch in order. Take off mounting screw below headlamp switch on dash for E36 models. To remove trim panel, use a soft plastic wedge to ease it out. Slide panel out to access connector through electrical wire harness opening. Undo this connector by rotating it anticlockwise. Disconnect the negative side of the battery terminal or post Remove screws that hold down bottom left of dash trim underneath light switch. Remove panel Remove the cover with its attached switch from vehicle's console by turning counterclockwise disconnecting plug and removing it All of these steps will be easier if you put masking tape around your car's lights so they don't get damaged when trying to remove them The lightswitch knob can be removed by covering it with tape then pulling it away from where you normally turn on your headlights Instructions on how to install a new one are provided below Put together -up lots of nuts, connective cords and switches first before screw-drivers are assembled in place Take Out The Knob Of The Light Switch And Cover It With Masking Tape In Order To Prevent Scratches On It When Removing From The Dash Mounting Nut At Shaft Is Removed By Wrench Or Socket Before Pulling Out Switch Now fit tab at other end into slit made in dashboard Connect wires Back Fit this panel into dash You may have to insert a thin long shanked screwdriver through vent while lining up dash vent with duct in dash Do not jam or push hard as board will break or scratch while being placed Screw down after positioning.