Question about upgrading tickets

I want to buy a 7 day wpm hopper from undercover tourist. If i want to upgrade to more days can I do that when I get there? Also how much extra would it be?

Yes, you can do that once you get there. Just use it to enter a park once and then go to Guest Services to do the upgrade. From a 7-day PH+WPF&M it will cost you $10.65 per day.

Awesome thank you!