Thank-you so much to everyone that has replied! You have given me hope. Unfortunately, the change was made a few days ago and it has already be ticketed.

When I talked to the American agent on the phone, she sounded very sympathetic and friendly, but she was unable to change the flight without the large fee I mentioned.

Does the airline keep a record of each call? If I call again, will the agent know I have already called to make the same request? I am assuming a supervisor would have to ok the change, or does the agent have the authority?

I will also ask my friend to ask for help at the American ticketing agency in his home country.

As a back up option, I am using Kayak to search for a round trip ticket from the city he is now scheduled to fly into (NYC), to my home state in the midwest. I have always had luck using Kayak to find the cheapest price when I fly, but I usually start looking at prices a couple of months in advance, and make the reservation when the price hits rock bottom (usually a month or month and a half before departure). In this case, the round trip tickets normally start at around $250, but we are now less than 3 weeks before departure and the tickets are more than $400.