Discharging cylinder on FX Boss, Sal

The valve in the bottle, if working properly will stop the air from leaking out. While you can stick something in there to let the air out it would be much easier if you just slightly unscrewed the nut in the bottom of the action that holds the screw that keeps the stock in place. Only unscrew it slightly and the air will leak out with the bottle on the gun. When tightening that nut back on only hand tighten it enough to seal the O-ring backup. If you put too much pressure retightening that nut you could snap It off since it is hollow to allow for the hole that let's the air come out.