The OP is merely asking how to modify those rules.
My understanding was that he never wanted the extension in the first place, but he couldn't get the original rule to work otherwise. That's where you have to suspect interference from something else in htaccess.
In any case it is good that you are hammering all this out in WAMP ahead of time. Much better than getting the whole site up and running and then deciding six months later that your naming system is all wrong :)