Depending on the year and configuration of the attachment locations can vary.
Front bumper
-open the hood.
-under the hood, Unscrew the two screws and take out the two clips that secure the upper part.
-Unscrew the screws that attach the lower part.
-remove the grille fog lights.
-for grilles Unscrew the two nuts.
-wrenched the wheel to the side.
-wheel arches Unscrew two screws on each side 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.
-with the assistant pulls the bumper forward (look for wires).
-switched the hoses to the headlight washers (if any).
-release the connectors on the Parking sensors, fog lights, temperature sensor (if any).
Rear bumper
-open the trunk lid.
-in the trunk and remove the rear side trim.
the side casings, in the inner part of the wings, Unscrew two screws on each side.
-the plating of the rear panel Unscrew three nuts.
-take out the rivets that attach the lower part.
-in the wheel wells, Unscrew the screws and peel the fender liner (rear part).
-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.
-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 SLK R170
How to remove front and rear bumper Mercedes SLK R172