sign in the official website of American Airlines

checks you're all booking with your last name & phone number. 

select your booking and select edit in booking. 

now select destination then if you want to change in the destination.

select Date and time if you want to change timing or date of Departure.

if you want to change the first or last name of the person you can change it by selecting the personal information.

if you need an instant solution if can't change reservation contact American Airlines Customer Service.for more info visit