Depending on the year and configuration of the attachment locations can vary.
Front bumper
-remove the license plate.
-under the license plate, Unscrew the two screws.
-Unscrew the two screws in the lower grille.
-(if there is) Unscrew the screws at the bottom (spun up).
-wrenched the wheel to the side.
-in the wheel wells, Unscrew the screws and peel the fender liner (front part).
-with the assistant pulls the bumper forward from the rails in the wings (look for wires).
-release the connectors for fog lights and temperature sensor (if any).
Rear bumper
-open the lid/liftgate.
-on the perimeter in the opening of the trunk, Unscrew the plastic nuts.
-(if there is) Unscrew the screws 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 holding the bumper corners to the wings.
-with the assistant pulls the bumper back from the rails in the wings (look for wires).
-snap together the connectors of the equipment (if any).
How to remove front and rear bumper Mercedes Vito/ Viano V-Class W639
How to remove front and rear bumper Mercedes Vito/ Viano V-Class W447