Bought PH Tickets from Undercover Tourist-Can I upgrade to Water Parks Fun and More?

Hey Everyone,
We bought tickets a few months ago (5 Day Park Hoppers) and now are considering doing things like Disney Quest and Water Parks when we go in two weeks.
Can we upgrade our tickets to Water Parks Fun and More?
How do we do this?
Has anyone done this?
Thanks!

Also, do we have to go to the parks first or can we go to Disney Quest first?

Yes, you can upgrade the tickets. However, unless you use a park entry first, you will lose the discount you got from UT.

Yes to what @brklinck said.
We’ve done it several times before. Once it took 15 minutes (with a new CM), the other time it took 2 minutes (with a CM who barely spoke english, looked brand new, but was so efficient I wanted to kiss him afterwards). First they convert your UT ticket to a MYW ticket ($0), then they upgrade to WP@M. Has to be done at Guest Services, either at a park or at Downtown Disney.