I did the same thing on my -4 some years ago. Skybolt included a pretty good instruction set. In short, however, a strip is rivet to the firewall to receive the Camlocs. In order to install this strip, it is necessary to remove the plate nuts that hold the forward fuselage skin in place. Some careful hole duplication is required to ensure the skin fit nicely again. I switched to floating plate nuts at this time to provide a little more forgiveness.
Next, you need to remove the old hinge strips from the upper cowl. I also replaced the original formed hinge (between the upper and lower cowl section) with extruded hinge with wider flanges to provide better bonding surfaces. (Why Van's provided that roll-formed hinge stock I will never understand.) I had to do some fiberglass work, but cannot recall if it was dictated by the Camloc installation or for the hinges. I do recall, however, that the Camloc instructions recommended the addition of a fiberglass stiffener along the curved portion of the upper cowl, just forward of the Camlocs. This is to eliminate/reduce puckering between the Camlocs while in flight (due to the ram pressure of the cooling air). I skipped this step, but wish I had complied as I do see some minor puckering in flight.
You will need to re-paint your cowl once you are done. I did this task about 10 years ago, and it all still works and looks great. I would call Camloc they must have these instructions.
Good luck.