Changing Southwest tickets & a decision to make today.

I've got a flight booked for Vegas on 8-26, returning 9-1. Today I received from Total Rewards free flight and accommmodation for two to Laughlin 8-23 to 8-27.
If I decide to take the TR offer what do I need to do with my Southwest tickets? Do I just call them to cancel and then they have me down for credit on a future flight? I don't want to delay on choosing because you never know how long you have before the free flight offer fills up.

 

You can call or go online to cancel Southwest. They will give you credit for up to one year from the purchase date. Easy peasy.

 

You MAY be able to book the TR trip and cancel at a later date w/o a penalty..I did a trip in April and remember something about a cut-off date for no refunds,but forget if there was a fee..May give you more time to think it over..call them.
But cancelling SW should be no problem,just use the credit within a year.GL

* Oh Shoot.Misread your 'Free Flight' ..Thinking it was like mine for $150 or so..