yea they can suck,,u could drill it out as long as u can get a new screw,,u can try to apply pressure under the screw head as u turning it to see if it might help,back it out and lock the nut in place with the applied pressure,,,or as stated above use needle nose pliers or a small set of vise scripts to lock on it ,,and of course use some wd-40 or pb blaster to soak the threads