The front isn't a problem. Unscrew front bead. If it's a 6x48 you can use as is for front screw in ramp. If not D&T 6x48 using it for pilot hole. Screw ramp down and mark rear hole, D&T and make sure yor screws are flush with bore inside barrel. Some put back sights on with JB Weld or epoxies. These work but I silver solder mine, not easy unless you have soldering experience and the right solder & flux. It's easier to D&T for reciever or ghost ring type sight. Using same #31 drill bit & 6x48 tap used on front.