I just picked up a pristine 81 DL that is missing the rear peep sight. It appears as though there is a blank in the rear sight dovetail that needs to be removed so that a new buckhorn sight that I picked up from Numrich's can be inserted in the blank (now screws or screw holes). Just curious if there is a "trick" to removing this so that I'm not pounding in it with a drift and hammer. Any advice would help. Thanks!