The easiest way is after unbolting everything, give it a quick pump and the valve will blow out the back. Leave the bolt in the valve until the pump handle is open to keep it from being vacuumed up the tube opening the pump handle.
That was a great tip from psipumper about keeping the bolt in the valve until the pump arm is opened all the way up.Be careful how the back end of the gun is pointing. I believe it was Avator who said he once blasted the valve into his "nether regions".
It's been a long time since I removed the valve from my 392. I am trying to remember now, seems there was a small screw of some type, maybe setscrew that was in the way. Forcing it would gouge the valve. Just mention it as you may look for something like that...
I have been following your posts so I figured you probably had seen this short video.
What nobody seems to remember to tell you about removing the valve is that you need to put about 4 or 5 pumps in the valve first, BEFORE you remove the trigger assembly and try to "PUMP" the valve out the back. If you don't put those 4 or 5 pumps in the valve first, when you try to pump the valve out the back the air goes in the valve, like it was designed to do and doesn't really push the valve back very far at all. And usually not near enough to grab it and pull it out. And also, depending on how deep the manufacturing stamping is on the side of the pump tube, it may make the valve a little tougher to get out, but it will come. I had one gun that took 5 pumps in the valve and a little oil dropped down the pump tube from the rear to help the valve slide out.Hope this helps. I wish someone would have told me this before I started working on my 392. Ray