This probably voids the warranty or if you break you stuff not my fault!
The only reason to do this would be for anodizing or just to do it preform at your own risk.
Unscrew lower section of reg.
Remove reg section denote valve. (brass thing sticking out of top part of reg)
Take needle nose pliers and loosen the valve, then unscrew it by hand to prevent damage.
Insert two allen wrenches like so, I used 1/5th sized wrenches that are long for added torque which is needed. It takes a lot of force to loosen this at least with mine it did so be careful.