I forget exactly how I did it, but it involved needle nose pliers with rubber on the jaws. The ratched threads are REVERSE if you did not know, and staked so it may require a tad bit of force but be gentle. After the ratchet comes off I think the cylinder will come off the ejector rod. I swapped the cylinder on one I had so I have taken it completely apart.
I expect Starpuss to chime in with his vast experince with these guns.