Remove the two front covers (UG3.1) and (UG4.1) from the left and right roller rails (UG3)
and (UG4).
Loosen the four hexagon socket head screws (UG2.1) on the cross bar (UG2) by means of
the supplied hexagon socket wrench (IM).
Slide the cross bar (UG2) into the lateral guides of the left and right roller rails (UG3) and
(UG4). When doing so, make sure that the washers of the four hexagon socket head screws
(UG2.1) are located inside the roller rails.