Stripped plug FX Wildcat

Spyguy,
Don't know the MK2 but you're lucky to have a way to empty the cylinder, my MK3 has no such device. I've only a brass pressure adjustment screw, which can be found after removing stock. I'd verify this procedure, prior to attempting, but read of shooting pressure down, then slowly loosening gauge to vent remainder. Members would respond if questioned on this, I'm sure. Best of Luck, WM
 
Use an EZ OUT tool/bit
Or slowly loosen front manometer and when you start heating air hiss out stop loosening and just hang for a bit.

If it were me I would completely drain the gun of air via the loosening of the gage, then the lack of any air pressure may cause that brass plug to easily be removed.

I wouldn’t fire the gun to empty the air out. The Gun relies on pressure behind the valve stem so as the hammer striking it doesn’t inflict so much pain on it. There will be a point typically when below reg pressure where the hammer strike is greater than the pressure behind the valve rod and that’s when damages can arise
 
I striooed the brass plug on my FX Wildcat MK2. It's the one that empties the air cylinder. Any thoughts on how to remove it? Or any thoughts on an alternative way to empty the air cylinder? Seems easy to strip screws and plugs on this gun! Thanks.
were you using hex keys with the ball end? those will stripout a set screw quick when under pressure or tight,