When  you SET a preset with the G4 Joystick Controller, this information is saved to the camera, not the controller. When the preset is CALLED the information is retrieved from the camera.

Once you get the camera added in you can go to "Settings" and then "Preset Setting" and type in the one you wish to clear and click "Clear Preset". 


Also, if you add a new preset, this would overwrite the old/previous preset.