Never had to remove the front sight of my Shield 40, but have had the rear sight off several times. No LocTite on the rear sight, just the set screw. Since the sights are factory pressed on, they are hard to remove. I clamped the slide in a vice and wrapped the slide to protect it. It is best to use a brass punch (also wrap the end of the brass punch in tape). I used a steel punch and taped the end up. Keep turning the punch after every blow, to prevent metal to metal contact, and re-tape if necessary. Knock the sight out from the left side to right side, looking from the rear to front. Do not try to punch on the bottom, thin lip, of the sight. Put the punch on the thicker area, just above the lowest step/lip. It takes quite a bit of force and it will start to move.
Do not knock it fully off. As you get close to the end, pull it off by hand. There is a spring on the blocker, which is under a small amount of pressure. There is a small cap on the top of that spring. Be careful not to lose the cap and or spring.
Bob