This replaces the complete case on the Logitech C270, you just keep the cover and PCB screws, PCB board assembly and cable with gromet.
To remove the PCB, remove the three front cover screws, remove cover, remove the two screws holding the PCB in place. Carefully cut the original back case with your cutters so as to be able to remove the complete cable. You will reuse the gromet.
If you are unsure of destroying your original case, twist and pull the rubber gromet back on the cable so you have some slack. Remove the PCB while the cable remains in the original case and temporarily assemble in the newly printed case. If you like it, proceed cutting your old case; if not, reassemble original case and let me know if I should change anything.
If you would like Mainsail to include the option to have the crosshair overlay on the nozzle cam, please upvote here: https://github.com/mainsail-crew/mainsail/issues/1868
The author marked this model as their own original creation.