Many thanks to pollyb for saving this from the old site.

The question often comes up "How do I get the grip screw out?" Here you go, the poorly illustrated version. The firearm used for the photos is a UC9, others are similar.

This is the infamous screw. The grip retainer is really not a screw, as you will see.
First, with a suitable screwdriver, about 3/16 flat blade with a good handle. You need a good grip on the screwdriver. Push the retainer straight in .200 +/- , then turn gently to the right, the reason for going right you will also see. Do not force the retainer, when it is pushed in far enough it will turn easily about 1/8 turn.

The retainer is now in this position (under your grip still). Now you can gently just with your fingers in the magwell push the sides of the grip out slightly and slide the grip off toward the rear. Don't spread the grip any more than is absolutely necessary, it can cause it to fit loose later. If it does, heat the backstrap with a hair dryer or a heat gun if you are careful and squeeze the sides together a bit to snug it back up.

This is the retainer in the normal position, the taper is what fits into the grip to hold it in place.

This is the taper in the grip.

I decided to take one for the team and remove the retainer for a pic. It's not really too big a deal unless you don't know its about to come out. The hammer spring will toss your screwdriver across the room if you aren't expecting it.

The reason you turn to the right instead of the left is clear in this photo, the short slot is where the tab normally sits, the long slot is how it it removed. If you do want to remove it, turn to the right and remove the grip first, then to the left to release the hammer spring and strut.

Reassembly is simply the reverse.