I'm back at home...logged on to mytickets and I can't exchange them. The other game that was postponed, can't remember what game it was, but it think it was a Thursday, I went to the box office Friday afternoon to exchange it because it is fairly easy to get there from work. If they do a double header tomorrow, I can't get there before they'll re-start it...I remember that Thursday game they were saying it had to be exchanged prior to the start of the rescheduled game.
If it has to be at the box office, in the rain, with 15,000 other people, that wouldn't surprise me. I doubt they actually want it to be convenient and hope people just give up.