View your reservations on the American Airlines website. Click on "My Reservations" and log in. Choose the option that allows you to change your travel date. If your reason for changing the date of your flight is due to a death, health issues or military assignments, call American Airlines directly to discuss your change with an American Airlines representative, who can make your change without penalty.
Change the date of your reservation when prompted to tell American Airlines which changes you'd like to make to your flight.
Confirm your flight changes and pay the penalty, which is between $50 and $100 depending on your specific flight. The change fees will not differ if you change your flight by one day or by several weeks. If you think your change should not incur charges, call American Airlines' reservations line for assistance.