The front sight is on a wedge system. On mine, taking a punch you drive the old one out and then the new one in. The back system, the new wedge base has a screw hole that you set the sight over that and then put their lockingscrew in place to hold it all together. The other part slides on the back sight ramp and is held in adjustment by two screws. It took me about ten minutes to change mine over. These look to be the same kind as mine.