Mount the backplate to the arm with 2x M3x8 button head screws.

Mount the ball to the arm with 1x M3x8 socket head screw.

I also used a drop of superglue.

Insert the PanelDue into the backplate lining up the screw holes. Screw the backplate to the front plate with 4x M3x10 button head screws.

Mount the full assembly to the front frame re-enforcement with 2x M5x10 button head screws and 2x M5 T-nuts