WOOO talk about timing, hunt starts the 23rd so today was the last day. Got ahold of DFW at 4 pm and they said where to mail, got to the post office about 5 minutes before they closed at 4:30 to make sure it was stamped today. 
Honestly, I had exchanged the same tag last year (that time because I was successful in the early season) but had forgotten the process. I thought it was an online system. 
Thanks for the help!