Depending on the year and configuration of the attachment locations can vary.
Front bumper
-open the hood.
-under the hood, Unscrew the six screws and release the latches (in front of each screw to pry up with a screwdriver) that secure the top.
-in the bottom part Unscrew the screws that secure protection and take out the rivets that attach the fender liner.
-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.
-with the assistant pulls the bumper forward from rails (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 behind the paneling of the rear panel Unscrew the nut.
-take out the caps and Unscrew the screws that attach the lower part.
-wheel arches take out the caps and removed the wheel arches (rear).
-move the wing flaps to the side and take out one piston on each side that attach 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 electrical equipment.
How to remove front and rear bumper Mercedes SLK R170
How to remove front and rear bumper Mercedes SLK R171