Clamp muzzle brake in padded vise jaws.
TG you said that before me. Sheesh. That spring-loaded detent is there to clock the slant-brake in the right direction for muzzle climb reduction when in full-auto. Takes less time to remove it then it does to type this.Good lord!!!! DO NOT CLAMP the muzzle brake in a vise!!!
There's a detent on most if not all AK's behind the slant break. After checking if the weapon is clear, simply press in the detent with your finger and unscrew the slant break. That is, of course, if it isn't soldered on.
It's the little thingy sticking out of the front of the front site base. It's spring loaded. It's also there so you can clock a slant break for left or right handed individuals.