there is a staking tool that works really well, If you are going to be playing around with 1911's it is worth the cost...
If you just get a smaller center punch and another person to help, it is usually possible to do it yourself without the tool. Place the sight with a dab of locktite on the shank into the mortise, have the other person hold the slide upside down and firmly against a solid steel surface that will work as an anvil. A real anvil works the best but the back of a vise, or a really solid chunk of bar stock can work too, With the sight pressed into the slide and the slide held firm place the center punch on the tab and strike it smartly with a hammer, slightly move the punch and strike it again, the idea is to strike the shank in such a way as to mushroom it out and thus prevent it from retracting back thru the mortise, You do not want to ever touch the slide with the punch, but rather to strike the tenon of the sight in such a way as to move metal away from the center and out toward the edge,
