The headlight bulb is accessed through the back of the headlight. You have to remove the gray cover by pinching the tabs at the top and lifting straigt up. There is a retaining ring that holds the bulb in place. Turn the ring counter-clockwise and then slide the ring away from the assembly. Pull out the bulb and it's housing. Then unclip the socket from the bulb. You can do this step before removing the ring if you can actually get the socket to release - I couldn't.