1. Boil water in a pan, submerge mount/threads into it and leave it overnight. Try not to leave too much of the barrel in there if you can help it, though it won't hurt if you clean it good later.
2. In the morning or next day, do this again. Leave it in the water for ten minutes or so to heat back up but before the water is cool, remove it.
3. Have your reaction rod or barrel vise setup and quickly put it on (for removal).
3. Should wrench right off now.
A little heat from the torch can help, but only after you've soaked it like this. It'll "crack" easier like the guy above said if still stubborn. This is what works best for me. Quickly clean it with a brush and pick after it comes off and before it rehardens and it'll be much easier to clean. Be sure to get it all out then.
For reinstallation, I prefer red Loctite due to the hassle with Rocksett and apply a bit more torque; they make a permanent green Loctite, don't know much about it though or if it comes off at all. If they used a LOT of Rocksett, it can be a real bitch to get off, especially if torqued down. You don't need a whole lot of torque on these mounts when you use Rocksett or another strong thread locker, but they get overdone more often than not. I forget which mfg., maybe AAC? They use Rocksett. They said to use one or two drops at most, hand tighten and then give it a snug turn with a wrench. That's it. I've done that and it works, still had to do the above steps to remove it. That stuff works, but it can be a bitch to remove, depending.
Good luck! The above should make it a lot easier though.
