We have been planning on going to WDW 4/20 - 4/26, but the airfare has remained higher than what we want to pay. However, the airfare for 4/27 - 5/3 has dropped to a good price. While this is not ideal, we could change to those dates. If I book those dates and then the price for the dates that we would rather go drop later, can I change my airfare dates with Southwest without a charge? How do I do it? Is there a certain way I should book the tickets I originally purchase to make it easier to change later? There are 7 of us. TIA!