the front sights are "pressed" in, and to remove one we put the blade in a "SMOOTH" jaw vise, and lock it on tight, we use the end of the vise ( left or right makes no matter) and the gun itself will be sticking up in the air, perpindicular to the flat of the vise top, then take a plastic hammer ( or leather mallet) and give the top of the barrel a GOOD rap to knock it off and away from the sight blade.................
to reverse, we put the barrel in the vise sideways ,use a piece of leather to 'pad' the BOTTOM of the barrel, at the front, and a flat piece of "hardwood" over the top of the sight blade, slowly close the jaws of the vise, to "press" the sight back in, some folks will ut a drop of loctite in the slot beforehand, but they usually do NOT come back out unless you "wiggle, wobble, distort the 'slot; in any way OR file down, (narrow) the blade in any way..............take your time, "neatness counts" hate to see a "boogered job".