Also the stripped out allen socket in the head of the screw works as a perfect center for the drill bit. All you need to do is drill deep enough that the head of the screw pops off, then you can remove the trigger pack. Then go at the remaining threaded stub from top or bottom with a pair of tightly clamped vice grips to screw it out or all the way through. Once you get the trigger pack removed it also allows you to chip away the glob of thread locker, if present, and allows you to get in and apply some heat to release the thread locker, if present. It is not difficult and can be done with a cordless drill in minutes, just go slow.