The original Honda spare part has code 17620KAF003 - CAP COMP., FUEL FILLER. To disassemble it:

1. Remove the metal ring under the rubber gasket. It is necessary to spread the gasket with two or more screwdrivers and you must rotate the ring so that the notch aligns with the tooth.
2. Under the metal ring there are three screws that secure the locking mechanism to the fuel filler door.