I have never flown stand-by before (intentionally anyway). I have booked a 5:30 pm flight DFW/PIT on AA, but now want to depart on the 12:40 pm DFW/PIT AA flight the same day, and would rather not pay the $100 change fee. Is there anything I need to do to fly stand-by? Call and be put on a list? Just show up?

Thanks for your help....