The reverse_bowden_x-axis.stl piece has to be glued (double sided duct tape or other similar things). The reverse_bowden_x-axis piece can be screwed on the left side of the X axis, by removing the existing screw from the plastic casing, and using a M3x5mm one to anchor the reverse_bowden_x-axis piece in it.
The author marked this model as their own original creation.