Click on the "Travel Center" and click on "Change Air Reservation" and follow the prompts. If the lower fares exist for your flights, you just choose them. As I remember, it's pretty effortless. For $60 though, keep in mind the credit must be used for TRAVEL within one year of initialy BOOKING date. (e.g. if you book in July for a november trip and then change the reservation and end up with a credit, you must use that credit for a trip the is completed before July.) Maybe make sure you can use the credit. Some people have been successfull in getting refunds, but that isn't always the case.