You should check the brake lights on your Mini Cooper every six months to verify that they are working properly. If they're not, you'll need to change the bulbs. The Mini Cooper's brake lights are accessible from the rear hatch area, and you'll need to replace them with the correct bulb. Fortunately, the bulb part number is located on the base of the bulb, and replacement bulbs are available at most auto parts stores.
Pull the liftgate release lever in the cabin and open the Mini's rear hatch area.
Unclip the light bar. On the left and right side of the Mini in the rear, there is a clip holding the light assembly in place. Remove this clip to access the brake lights.
Squeeze the release tab on the top of the electrical connection and remove the electrical plug from the bulb ballast.
Turn the bulb counterclockwise and pull it straight out of the tail light housing.
Insert a new bulb and put the tail light assembly back together.