There are a few different ways to remove an AUG flash hider, depending on the model and configuration of your rifle. The most common method is to use a flash hider removal tool, which can be purchased at most gun stores or online retailers. Simply attach the tool to the end of your AUG barrel and unscrew the flash hider in a counter-clockwise direction.
If you don’t have a flash hider removal tool, you can also use a vice and a pair of pliers to remove the flash hider. First, secure the AUG barrel in the vice so that the end with the flash hider is facing up. Then, use a pair of pliers to grip the base of the flash hider and twist it counter-clockwise until it loosens and can be removed by hand.
Once the flash hider is removed, you can either leave the barrel naked or install a new muzzle device of your choice.