Depending on the year the site of attachment differs.
Front bumper
-open the hood.
-under the hood, Unscrew the two screws that secure the top.
-Unscrew the screws around the perimeter of the bottom (spun up).
-wrenched the wheel to the side.
-wheel arches take out the side caps and removed the wheel arches (the front part).
-attach the fender liner to the side and Unscrew one screw on each side holding the bumper corners to the wings.
-pulls the bumper forward from the rails in the wings (look for wires).
-snap together the connectors of the sensors and the temperature sensor (if any).
Rear bumper
-open the trunk lid.
-in the opening of the trunk pull out four plugs and Unscrew the screws under them.
-from the bottom Unscrew the four screws that secure the lower part.
-in the wheel wells, Unscrew the screws and peel the fender liner (rear part).
-for wheel arch liners Unscrew one screw on each side holding the bumper corners to the wings.
-we release the latch in the wings (pull the corners themselves).
-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 W176