The screw will probably be in the #4 to #8 range, hard to find ease outs in that small a diameter, is any of the screw sticking out??? If so, you may be able to heat it up, I would use a soldering iron in this application, applied directly to the screw, until it starts smoking, and if you do have some bee's wax apply it, as it will get sucked up into the threads, and help, grab the remaining, exposed piece and unscrew it. If nothing is sticking out, then drill it out as centered as possible, right hand or left hand does not matter, as you are now going to go the next size larger, not 2 or 3 sizes, but just the next, and retap the hole and install the next larger screw. I went to brownell's website and they do not give the diameter and pitch of the original screw. But you can go to several websites for the proper size drill for the next larger size, if you don't already have a chart. This is a very solvable problem, and your learning some basic smithy traits... If you don't get where you want to go, PM me and I will help.
Range members, Leatherman, is one of our youngest members, but heart and soul.