Unlike most vehicles that have side marker lamps on the turn signal assembly, the E320 has a separate assembly solely for its side marker lamps. To replace the lamps, the entire assembly will have to be removed from the vehicle. It's actually a simple job that requires only a replacement bulb. The E320 uses a 5W bulb, which can be purchased at most automotive parts suppliers.
Turn the headlight switch to the off position and put on the gloves.
Slide the side marker lamp unit toward the front of the vehicle. Remove the rear end of the unit first.
Twist the bulb socket counterclockwise and remove it. Pull the old bulb out of the socket and push in a new one. Reinstall the socket by pushing it into the assembly and twisting it clockwise.
Reinstall the lamp by placing the rear end into the bumper and snapping the left front end into place.
