Well I use a brass bar to remove or tighten muzzle brakes. Your brake is stainless steel I believe and no way a brass bar could harm it that I could think of. And i'm guessing you know the alternative;
Use a split clamp wrench or the Badger Ordnance compensator wrench P/N 1005-306-35. If you don't have all that then secure the barrel in a vise and of course protect it with something so it doesn't mar it up. Next wrap something around the brake, I use some semi heavy leather, take a pipe wrench and adjust for a snug fit gripping the leather and give it a pull. If lock-tite was used during installation i'll take a heat gun and get things warm first.
I'd use a brass bar through the ports and give it a wack which is the quick and easy way, but your brake and your choice. Hope this helps out.