darxtar, not sure why you need a drill. I took mine off and made a muzzle brake for it. Works great. As I recall, there is a small disc pinned into the threaded part of the flash hider/muzzle. This is near the bayonet lug. Drive out the pin with a punch, remove the disc which locks the threads, and turn the hider off. There will be an adjusting shim inside the hider so don't loose it, you may want it later. The thread on mine was 9/16- 28, I think. I can check on that if you like. R H thread, by the way.