Place the cylinder in a vice with protected jaws. The vice should not grip the area where the internal is threaded. We recommend using protection to prevent damage to the cylinder.

Once you have gripped the tube correctly,  then take the levering bar and slip it into the filler hole.  Make sure the bar goes right through. Then whilst gripping the body of the tube protruding out of the vice with your hand, push/pull down on the  steel bar.  Commonly it is really tight – in this case we recommend giving a short, sharp whack with a rubber mallet to crack the seal rather than applying slow, gradual force which will just result in you bending the rod.  Note: some can be REALLY tight.