three mode into one

So, yet another potentially dumb question...

I received my Rominsen torch from guess who, I specifically bought it as it was advertised as single mode and I only wanted a single mode light as its destined to live atop my rifle operated by a pressure switch.

Well guess what? Its a 3 mode so my dumb assed question of the moment is;

Can I make it into a single mode? Its a RC-G4 btw.

(I've already got a pretty good idea what the answer will be but what the heck, ask the spurts is what I say!).

Thanks in advance for your help folks.

It's pretty easy to go to one-mode, just pick up a driver from the shoppe and swap it for the current driver.