Base ticket upgrade?

[vivaciousdame]

HI All,
I can't find this answer in the Universal FAQ so I'll just ask here. We got the Harry Potter Celebrations package and it comes with 3 base tickets for each of us. HOwever I'm wondering if there is a way to upgrade to "park to park"? (I think thats what it is called) Like Disney is there a way to upgrade at the park or are we just out of luck?
(I don't think we were given the choice of upgrading, I can't remember)
Thanks!

 

[Metro West]

Normally you could upgrade but I'm not sure how the package will affect the tickets. You may not be able to...I'm just not sure.