Changing state used in tax return

I completed my return with my state.  Now I want to analyze my taxes using a different state in case I decide to move to a new state.  I know I'd pay for a second state software.. 

But how do I change state without messing up my real return?   Is it as simple as making a copy of my return and name it "fake", then delete the current state?  That sounds like it'd mess things up.