Well, you need the tools, and you need the patience.
A properly installed muzzle device is attached with Rocksett, and does not remove easily. I am not sure what a UIC pistol is, but you will need to hold the receiver and/or barrel in place in a vice in such a manner that you do not injure the barrel, barrel extension or receiver. But, before you do that, you will need to treat the muzzle device. Many methods. Easist is a soak in hot soapy water. I prefer to dunk into an ultrasonic cleaner with cleaner and water and heat the water. You can also apply direct heat (torch). Those being in inverse order of time. soak should be 8 hours, the ultrasonic around 40 minutes, and the torch not too long. Then use the three prong Surefire wrench, or the AAC socket and turn with lots of leverage and slowly, taking care not to injure the receiver or whatever is holding the barrel tight.
It will come off.
