We did this last year. What you do is get in line and give them your tickets. The someone takes them away for 5 minutes or so and brings you them back including a new ticket for that day.
I have to say that I kind of regret using them since they are so much more expensive then DL tickets. But it's what we had and the trip was spur of the moment and we didn't want to go in debt for the trip.
Jen