The specific procedure is to change the registered items. The steps are as follows: All it takes is for the existing patentee and the patentee to be added to draft an explanatory agreement. The content is roughly that the existing patentee agrees to add a patentee, and the rights are clear and undisputed. After the agreement comes into effect with each person's seal and signature, just ask the agency that applied for the patent at that time to assist you in going to the Patent Office to go through the procedures for changing the bibliographic items.