The "rivet" in this case is simply a plastic stud with barbs, molded into the cable guide itself. If you can compress the barbs, you can remove the cable guide. If the hole is threaded, you can drill out the cable guide's stud and just use a short screw instead, or go buy a cable guide designed to use a screw. If the hole isn't threaded, you might want to just shorten up the stud enough to clear the BB cartridge, and see if it'll stay in place reliably with the shortened stud and no barbs.