I bought tickets but ould like to upgrade to express How can I do that It saya they are nonreturnable

Guest service desk

Go to guest relations universal is really awesome like that

Yes you can do it there. Just get there early fast pass sells out early

Yes

You can also up grade to year's pass

After you walk through the entrance there is a desk to your left where you can purchase express and VIP upgrades. If you have any issues there is also a "Guest Services" desk to the right that is helpful for any questions/issues.

Go to guest service desk