My nephew, an infrequent traveler, already bought tickets to go on vacation with his girlfriend. Travel is SJU-MIA-MCO-MIA-SJU. When his father found out that they were traveling on AA, he added his AAdvantage GOLD # to his ticket so that he doesn't have to pay for luggage, have priority boarding & also changed their seat assigment from row 30's to 10's. Can this be done? Keep in mind that both of them live in the same house, and have the same name, except for their second last name. Fathers name is John Winslow Adams Richardson, sons name is John Winslow Adams Emerson. Fathers name on AA GOLD is John Winslow Adams, sons name on drivers license is John W Adams Emerson. Ticket was bought under John Adams.

Any thoughts on this, has anyone done this? Problems?

I posted this question on AA forum, but seems that it was deleted.