Are you just trying to replace the bulb, or remove the whole thing from the bike?
To replace the bulb, here's what the Service Manual says:
Remove the bolt and bulb socket cover from the rear fender.
Turn the socket counterclockwise and remove it.
Pull the license light bulb out of the socket and replace it with a new one.
Looking at the diagram, the bolt is installed pointing down, with the hex head at the top of the bulb housing.
2004 Red 1300S, Clayton Mod, Ultim. LowRider w/ Driv & Pass Backrests, wishmasterg Riser, Cobra Eng Grd w/ Floorbrds, Pass. Floorbrds, Honda Dlx Sissy Bar&Dlx Luggage Rack, Lightbar, 19" Memphis Wndshld, Memphis Lowers, TourMaster Zipper-Removable Bags, HDL Fender Tip, Chrome V-Radiator, Freeway Blasters, Turn Signal Beeper, Remote-Controlled LED Lighting, Backoff Module, X-Hinge, Garmin 2610 GPS