How to Change Southwest Flig Step 1: To change your flight, you must first visit the official Southwest website. Next, you ht have to Login from the official website and enter your account number, username and password. Step 2 – When you sign in, you will see four tabs at the top of the page. You must click on a flight to get there. in the dropdown menu. From the menu select Manage Reservations and you will be taken to change or cancel the reservation screen. You need to click Change flight. Step 3 – On the next page, you will see another self-service box that you will need to click on change reservations. You must also fill in your approval number with the first and last Name. Step 4: Click Continue to select the change option to go to the page where the details of your order will be available. There you will see the option to renew the selected flight where all the information of the previous flight will be available. To resume a flight, you must click to select a new flight. Step 5: The next page will provide information on all future flights with updated information Rate. You can choose the flight that suits you best and click continue. when selected continue your flight change will be confirmed.