Hi Elisha!
No problemo!! First, log on to
www.waltdisneyworld.com and once on the main page, under the large bar that reads 'Parks/Resorts/etc' there is a thin bar ...the first button on this bar reads 'my Disney Vacation' and has an icon of a suitcase beside it. If you click that and put in your reservation number, you can set up an account. A cast member told me that after you access your account, there is a button to click to make online payments...the button is in the upper right corner.
So, give this a whirl and I think that should do it. If not, give me a holler back, and we'll try again.
Then again, you could charge it to the Underhills!! If you have never seen "Fletch" or are not a fan of Chevy Chase, then this reference will have no meaning. If you do know what I'm talking about, good one!!
Either way, your payment issue will be solved. Have a Magical trip!! :)
Chris