Screw two screws into the wall at a distance of 80 mm (you can also hold the socket strip and mark the holes). However, only screw in the screws so far that the open screw holes still fit underneath.
Slide the socket strip with the open screw holes under the screw heads and place the socket strip against the wall.
Now screw in two screws on side 2 through the closed screw holes. The screwdriver must be inserted at an angle towards the screw so that you can get past the upper tab of the end piece.
