Re-steming a Regulator

[NoL]

Got a brand new reg here, has a cga580 stem on it, I want to put in a cga350 which I have the stem for. Heres my problem, the damn stems round, no way to grab onto it, and its in too tight to remove by hand. How would you recommend I get the stem to unscrew so I can screw in the cga350 to use my ethylene.

[NoL]

Bump anyone?

[monkey spanners]

Does it have a hex/allen shaped hole in it? Like the uk ones. Failing that i would take it to a welding supplies shop as they would deal in a lot of regulators and may have the correct tool to chage the stem.

[NoL]

Good idea thanks, no hex or allen, but going to bring to a place, that or file a flat groove to grip on.