Bumper Mercedes M-Class W164 and GL X164 attached practically the same.
Depending on the year and model of attachment can vary.
-open the hood.
-under the hood, Unscrew the four screws (spun down) that secure the upper part.
-around the bottom part Unscrew the screws and take out the caps.
-wrenched the wheel to the side.
-wheel arches pulled three pistons on each side and removed the wheel arches (the front part).
-attach the fender liner to the side and Unscrew the screws (1 or 2 on each side, depending on model and year) that secure the corners of the bumper to the wings.
-we release the latch in the wings (pull the corners of the bumper itself).
-with the assistant pulls the bumper forward (look for wires).
-release the connectors on the Parking sensors, fog lights, temperature sensor (if any).
-open the trunk lid.
-in the boot remove the side trim.
-for sheathing, below the rear lights, Unscrew one nut on each side.
-from the trunk, Unscrew one screw on each side inside the wings.
-Unscrew the four screws (twisted up) and take out two pistons on each side that secure the lower part.
-wheel arches pulled three pistons on each side and removed the wheel arches (rear).
-move the wing flaps to the side and Unscrew one screw on each side (spun upwards) holding the corners of the bumper 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 electric equipment in the trunk and take out the wiring harness.