I bought some of the Truglo Pro Series Magnum Gobble-Dot adjustable fiber optic sights for the Benelli Nova this year. I've never installed an adjustable sight on the rib of a shotgun. The gun has just the small bead and a small fiber optic bead at the end of the barrel now. Am I supposed to leave these on the gun or is there a way to take them out? Thanks for the help!