To perform this glitch, go onto any map that has a thin wall (Such as Solitary). Go to an area that has glass on the walls, then spawn a Turret. Place the turret at the wall with the triggers touching the wall which the player will no-clip through. Go to player mode, then enter the turret. Turn the turret around so the player is inside the area that is being accessed, then go to Monitor mode. You should be able to move around the area outside the map.