The best way is to use a universal sight installation tool. But, since you don't want to spend $400 or $500 at Brownells, try this. Take out the set screw. Use a small block of wood or a piece of thick leather and hold it against the port (left when looking from the back of the gun forward) side and use a punch to hit it. I found that lots of small hits work better than big hits. It comes out from port to starboard.