De Dietrich DFU1781FN Guide D'utilisation page 48

5. Screw a guide into the holes on the appliance side. Insert the sliding rail into the guide and
screw it to the door. Unscrew the guide to screw the last screw of the sliding rail to the door.
Then attach the sliding rail cover to the sliding rail.
Screw the guide back onto the unit by inserting the slide.