You will need these screws from the kit:
Simply screw on the head to the backplate with the screws referenced before in the 3 corresponding screw spots.
For more details on mounting the head:
https://wiki.coprint3d.com/kcm-set/Mounting-the-ChromaHead
More information can be found on the chromahead here:
https://wiki.coprint3d.com/en/chromahead2