Upgrade ticket question

[camouseketeer]

I am going to DLR for one day in Feb. If I buy a one park/one day ticket at the booth and then decide that I want to hop to DCA, where would I upgrade?

Would I need to stand in a ticket booth line again or is there somewhere else I can go? Guest Services?

 

[DangerMouse]

Guest services to the left of the Disneyland turnstiles will be able to upgrade your ticket, or the ticket booths in the esplanade.