If the headlights on your Mercedes W211 are cracked or weathered, you may need to replace them. Unlike some vehicles, the Mercedes W211 requires removal of some extraneous parts to change the headlights. The process is rather straightforward, however, you should expect this job to take at least an afternoon of removing fasteners and putting them back on.
Turn off your Mercedes W211, and prop open the bonnet.
Tape around the silhouette of the bumper and the headlight bezel to protect the paint.
Remove the push-lock fasteners in each wheel well. Pry them out using your pliers, or use the screwdriver as a wedge.
Remove the two clips below the lower portion of the central grille, and pull this lower portion of the grille upward and away from the bumper to remove it.
Remove the four 8-mm screws from below the lower bumper.
Remove the pair of screws in each wheel well holding the lower bumper to the fender.
Pull the lower bumper off the bottom front of the vehicle, just below the larger bumper.
Remove the two 10-mm bolts that were revealed when you removed the lower portion of the grille.
Remove the 8-mm bolts between each headlight cavity.
Remove the 10-mm plastic nuts in the front wheel wells using the socket wrench. These plastic nuts are near the push-lock fasteners you removed earlier.
Pull out the interfender panel near the wheel well. Look for the small screw that secures the fender to the bumper clamp. Remove this screw with a #20 Torx wrench.
Remove the last two front 10-mm bolts near the central grille holding the bumper to the vehicle. You should have someone hold the bumper while you do this. Pull the bumper off the vehicle and set it down gently.
Remove the four 8-mm bolts securing each headlight.
Pull the headlight slightly out of its cavity, and disconnect the four wiring harnesses from the rear of the headlight.
Install the new headlight by connecting the four wiring harness and securing the headlight in the socket with the four 8-mm bolts. Remount the bumper, lower bumper and lower portion of the central grille using the fasteners you have already removed.