I assume you mean a complimentary upgrade.
The best way is to smile enthusiastically and tell the desk clerk how excited you are to be staying at the
Disneyland Hotel, because you're celebrating... (a birthday. a graduation. your 12th anniversary. Walt's birthday. whatever.) Oh, and is there any chance at all that you could have a complimentary upgrade?
Upgrades are subject to all kinds of factors, including occupancy rates, what rooms are ready for assignment when you walk up, which way the wind is blowing -- and the mood of the desk clerk. Being really, really (genuinely) nice to that person should maximize your chances. And if it doesn't happen, don't take it personally.
Mary
MouseSavers.com