Hi, Anthony!
Even though you have that third day of
tickets, you will not be able to park hop in the same day without adding on the Park Hopper option. Unfortunately, this upgrade will run you about $60 per ticket (plus tax, price subject to change).
If at all possible, try to use that third day of tickets to visit another theme park! Stop in for some late night fun on your arrival day or do an early morning at a park on your departure day. A little bonus time in the parks could be a lot of fun!
Your tickets will be
valid for 14 days after their first use, so hopefully you will find a way to use that third day to visit an additional theme park. If you do decide to add on the Park Hopper option, this
upgrade can be done at any ticket window or Guest Relations. A friendly cast member will be happy to assist you and give you pricing to upgrade your ticket.
Wishing you 2 (or maybe 3!) magical visits to the Walt Disney World theme parks!
Cathy