How to Change Air Transat Fli ght All you have to do is make sure you call the official Air Transat customer service number. After that, they will make changes according to your needs in no time. IVR You must select the "Manage Order" button. However, if you wish to make changes online, you must follow the information below to change your Air Transat flight. You will only be able to make changes after placing your order on the official Transat Airlines website. Go to the official website of Air Transat. Now you need to select 'Manage order'. When selected, you must provide details of the reservation on the new page, such as the reference number and the name of the passenger. All. You will now see your order. You just have to open your reservation and you will see the option to change your flight. All. Select an option above and you will be able to choose a flight from the list. You need to make sure you choose a flight to the same place. You will receive a confirmation email once your changes have been successfully completed. Air Transat flight change letter. You can save an email. letter for future reference.