Station wagon
Removal
1. Open the tailgate and remove the trim, refer to Section Removal and installation the tailgate trim.
2. Open the cover (1) and remove the nozzle (2) from the cleaner shaft using pliers.
3. Remove the water hose (1) from the nozzle connection (2).
4. Unscrew the housing cover (3) of the wiper motor (arrows in the illustration) and remove the cover with a screwdriver.
Installation
1. Insert the nozzle connector into the housing cover and secure it.
(Article borrowed from the web portal: mercedesman)
2. Fasten the housing cover. At the same time, check the seal, replace it if necessary.
3. Place the hose onto the connecting element.
4. Insert the nozzle into the wiper shaft and secure. Put on the cap.
5. Install the rear trim, refer to Section Removal and installation the tailgate trim.
6. Close the tailgate, check the operation of the jet and adjust it, refer to the relevant section.