Let's see how to install the new spool holder.
First we need to place the support anchor block. It is positioned on the side of the front in the upper rear part, on the left or right side according to your needs. Then we support the anchoring block so that all the holes fall into the angle and mark in correspondence with them, we can therefore do 4 3mm holes and proceed by screwing the anchor block with the screws and locknuts.

Next we fix the wire support on the frame, also in this case we must mark the correspondence of the holes on the frame, in fact we will have to make a 2.5mm pre-hole and then screw the dibond support with the self-tapping screws.

At this point we can proceed with putting the cable glands which must be fixed with a screw and nut on the dibond, and a self-tapping screw when placed on the polycarbonate angle.

We insert the wire passing cable making it start from the support of the wire end until it reaches the right distance from the final position of the reel. To avoid cable movements, you could put some small clamps in correspondence of the cable glands, or if you have a hot glue gun, you can put some near the holes of the cable gland.
You can now load the spools onto the holder and push the filament into the cable until it comes out of the end of thread sensor.