18. Remove the repeater from the mounting hole.
19. Turn the bulb holder 1 counterclockwise and remove it from the repeater housing (see illustration).
20. Remove the light bulb from the socket.
21. Insert the new bulb into the socket and secure it.
22 Insert the bulb holder into the turn signal housing and turn it clockwise to lock it in place.
Publication taken from an online resource [MercedesMAN]
23 Insert the side repeater diffuser into the mounting hole first with the protrusion 2, and then press the diffuser until it is fully fixed (see illustration 26.19).