I think the answer to this question is yes, but want to ask here anyway. We bought tickets from Undercover Tourist for our trip in June. We are now looking at doing one of the backstage tours that requires park admission. Can we go to customer service after entering with the ticket and upgrade the ticket to add one more day? It would go from a 7 day to an 8 day ticket if possible. If my math is correct, it'd be approx $11 more per ticket to do this. I'm just not sure 100% that I can do that since we've never needed to add park days to a ticket before.