⬢Turn the printer around so that the PSU side is facing you.
⬢Locate the long metal profile (tch-mounting-insert) in the back of the top extrusion. It has five threaded openings in it.
⬢Place the xl-dock-cable-router (the plastic part) between the rear metal sheet and the aluminum extrusion.
⬢There is a screw protruding from the xl-dock-cable-router. The screw must be attached to the third threaded opening on the long metal profile. Look through the rear metal sheet to check if the cable holder is lined up with the correct opening.
⬢Push the Allen key all the way through a hole (bottom left in the pattern) in the rear metal sheet as well as through the plastic part until you reach the screw. Tighten it up.