Changing your name is a basic right, with the 14th Amendment often interpreted as protecting it.
Technically, you just have to start consistently using a name in the US.
Unfortunately, unless you have the funds to battle this to the Supreme Court, it's not really possible.
"Common usage" as a reason on a name change petition means, "Everybody already uses this name for me."
Ok, this might not be absolutely true.
Just get a few friends to call you this name a week before if you require a clean conscience.