you used to be able to do this without logging in to the WDW site proper and it was a fast and easy process. Now it's a PITA, if you will excuse the expression. I had to go back to the WDW-DINE number to cancel two ADRs this week because the online system wouldn't work properly. I knew it was too good to last ... it ain't Disney if their web features aren't cumbersome and don't suck.