The only way to 'remove' it is to get your ecu reflashed with standard software. I had revo taken off my old S3 as the car felt terrible with it. I went to get a new map from AMD (which was miles better) and they couldn't load their software because of the Revo software already loaded, so I had to go back to a Revo dealer to get it removed.
Disconnecting the battery does not return the car to stock or even stock power! It will return it to the generic Revo map meaning you loose any changes you made via the switch, but you will still have remapped power.