First off.....get a better screwdriver! Those POS screwdrivers that come with the bracelet will ruin it. I had to have a screw replaced because that screwdriver just wasn't the right size and totally warped the screw head slot. Even the SAs use a much better screwdriver in the boutiques. I went to Home Depot and got one that fits so much better and has a much better grip. If it's still stuck, get a little PB blaster or any kind of penetrating oil that will loosen the grime that builds up in there and essentially seals those screws. I went a little overboard on loctite and my screws wouldn't budget. Used some of that and it worked like a charm.
I had some difficulty a few months ago, needed to remove it to play volleyball...and it wouldn't budge. So I went to my local boutique, and they helped me out. They had some trouble as well, but got it off eventually.