Depending on the year and model of attachment can vary.
Front bumper
-open the hood.
-under the hood, Unscrew the five screws (spun down) that secure the upper part.
-Unscrew the screws around the perimeter of the bottom (spun up) that secure the protection and wheel arches.
-wrenched the wheel to the side.
-wheel arches take out the caps and removed the wheel arches (the front part).
-attach the fender liner to the side and Unscrew two screws on each side holding the bumper corners to the wings.
-release the fasteners in the wings (pull the corners of the bumper visas and yourself).
-release the clips between the headlight and the grille (pull the bumper forward).
-with the assistant pulls the bumper forward (look for wires).
-snap together the connectors with sensors, fog lights and temperature sensor (if any).
Rear bumper
-open the trunk lid.
in the trunk remove the plastic cover of the rear panel.
-the plating Unscrew the two nuts.
-from the bottom Unscrew the screws that attach the lower part.
-wheel arches take out the caps and removed the wheel arches (rear).
-the fender liner, Unscrew the screws holding the corners of the bumper to the wings.
-we release the latch in the wings (pull the corners themselves).
-release the clips under the rear lights.
-with the assistant pulls the bumper backwards (look for wires).
-snap together the connectors of the equipment (if any).
How to remove front and rear bumper Mercedes A-Class W168
How to remove front and rear bumper Mercedes A-Class W169