Hi there Diana,
Welcome to planDisney and thanks so much for your question! First, I'm thrilled to hear you're planning a trip to the Happiest Place on Earth here in a couple of weeks. What better way to kick off a new year?
In regards to your question, you are able to upgrade eligible theme park tickets - even to the
Southern California Resident Ticket Offer - as long as the new ticket is equal to or greater in value. I would recommend
calling a Cast Member at the Tickets line to check your ticket's eligibility and get this done. They should be able to walk you through the process and next steps.
You also mentioned that you want to keep your current
theme park reservation date, which I totally understand! I am happy to report that as of the time that I'm answering your question,
both parks still have reservation availability for the So Cal Ticket Offer on January 11. This means that either way you should be covered, but make sure to call a Cast Member as soon as possible to get more details!
Thanks again for your question, Diana! I hope you make some new magical memories on your upcoming trip to the Disneyland Resort.
Have a Magical Day,
Greg