I saw the following on Cheshire Figment's ticket sticky, but is this all still accurate? There have been a lot of ticket changes since the sticky was first made.
H. Upgrading a Completely Used Ticket
In some circumstances you may want to upgrade a completely used ticket. Normally this will have to be done when you have used all your major park entries and suddenly decide that you need more days, such as your home airport is closed for a blizzard or you still want to use more than one WPF&M entry.
This is not a problem if your ticket is either on a KTTW or a Florida Resident multi-day ticket. These tickets have your name preprinted on them and you will have to show a photo ID that this is your ticket. Without this proof it will require approval of a Guest Services Manager as an exception to policy.
Take your ticket to any ticket location as long as it is within 14 days of first use, and the total number of days on the ticket is less than ten. They will follow the same procedures to add extra days and/or WPF&M, add extra days and also the NE options, or upgrade to an Annual Pass. The same rules apply as for any other upgrade (as shown in Posts #6 and #7).
Note that a fully used Florida Resident three or four day may be upgraded at any time within six months of first use.