Included are STLs for installation jigs and bases for a Makita RT0701C Router ( for 1/4" and 3/8" straight bits). There are alternate files to compensate for slight variances in router bit sizes or printing tolerances. Added a DeWalt base plate for 3/8" bit. Test them all in scrap foam to see what works best for you.
If you don't have that router you can use a Dremel or other rotary tool and eye ball it if you are just doing one installation.
The jig is for FCS2 but I do have a jig for FCS Fusion as well.
Not exact instructions on how to use the jigs but you get the idea from my website https://www.geckosurfboards.com/surfboard-building-router-jigs/
The author marked this model as their own original creation.