In light of the fact that we recently lost all of our technical forum stickies, I thought I might document my experience changing out the CAI "loudener" (muzzle brake) on my CETME just in case anybody else needed to see how it's done. The pics are kinda bad because I couldnt find my camera so I took these on my phone. Hopefully next time somebody decides to remove their brake they will take better pics and we can replace mine with their's.
1: LOCATING THE PIN
The first step is to locate the pin that holds the brake onto the rifle. Turn the barrel to the 6 o'clock position and make a mark about a quarter inch from the bottom of the brake. Using a dremel tool or something similar, SLOWLY grind down into it, checking frequently to see if the pin has been located. You shouldn't have to grind down very far at all before you see a faint black circle in the middle of the grind; that is the pin.
The pin is not very tall at all, so make sure you do not grind too far, otherwise you will grind right through it and into the barrel.
2: REMOVING THE PIN
After the pin has been located, it must be removed. There really isn't anything holding it in there, so removing it is pretty easy. One method is to tap on the brake lightly until the pin starts to back out. Another way is to put a dot of super glue on the end of a punch, place the end of the punch on the pin head, let it set, and simply pull it out.
I used a magnet to pull mine out. Just put the magnet right over the pin and after a few tries it should come out pretty easily.
3: REMOVING THE BRAKE
Now for the hard part. After the pin is removed, it is time to twist off the brake. I believe Perro's method was to use a monkey wrench and torque it off, and others suggested sticking a long handled screwdriver through the muzzle brake holes and twisting it off. This works for some, but all i accomplished was breaking a screwdriver in half and the monkey wrench didn't do jack for me either.
Another popular method is to use a dremel cutting disk (or something similar) and cut through the holes on 2 sides of the brake to within about a quarter inch of the barrel. BE CAREFUL NOT TO CUT INTO THE BARREL ITSELF. CUT SLOWLY AND CHECK YOUR PROGRESS FREQUENTLY. Then, use a large screwdriver or a chisel and split the brake in half. This should loosen the brake enough to twist off.
After that, simply twist on your replacement muzzle attatchment. Viola!
Here's mine after I finished:
As you can see, not only does it look more original, it allows the bayonet to fit better as well. Hope this helps everbody.
The flash hider I used was a US made one from SSwee, a member of this board. I would highly recommend you purchase one of his flash hiders if you are thinking about replacing your brake.