It is held in with red locktite. Heat it with a hair dryer and use a fluted screw extractor to remove it.
Contact Mike Casady at CCI, and he will send you a replacement insert.
I know, I just removed and replaced mine.
Make sure you use a proper length screw on the new one. The button head is threaded, but you want the screw to engage as much of the threads inside the insert as possible, without extending past it into the inside of the gun.
Many people use too short of screw, and only engage the threads in the button head. It is the weakest part of that insert.
I have used three of those bodies now, and haven't had any issues. The 3rd one I bought with a broken insert, and replaced it. That's how I know how to remove it, and where to get a new one.
Walker
O.F.P.P.A. - OLD FARTS PAINTBALL PLAYERS ASSOCIATION
When you wrap-up the day with beer and Bengay.