Hi Nicole!
Welcome to planDisney! I'm glad you've been able to take advantage of the SoCal ticket offer. It's such a great way for locals to enjoy the parks!
It's usually possible to upgrade valid tickets as long as the new ticket is greater in value than your old one. I do see that the
SoCal Resident Ticket Offer includes an option to upgrade to
Park Hopper Tickets during the time of purchase, so you will likely be able to upgrade your ticket. You can upgrade your ticket at one of the ticket booths just outside the park gates, or you can try
calling the Tickets phone number before your visit. I would probably call in advance so you're good to go on Monday!
I do want to mention that if an upgrade is available you will need to pay the price to upgrade the entire ticket to a Park Hopper; you can't add hopping for just one day. Hopefully you have more days left on your ticket to take advantage of the upgrade!
Nicole, a full park day with friends is just the best! You are coming just in time for the
Disney California Adventure Food & Wine Festival, so your group will have the chance to
sip and savor your way through all the festival booths. Don't forget to visit
Soarin' Over California while it's back for a limited time!
Keep moving forward!
Amanda