Hello Cecil,
Park hop 'til you drop! I love the flexibility that the
Park Hopper option gives you during vacation, especially if you are staying at a resort that is close to Magic Kingdom or Epcot. You can easily start your day in one park, go back to your resort and rest, and make dinner reservations at another park where you can end your magical day. You could also do all four parks in one day if you were REALLY ambitious.
Right now, if you have the Park Hopper option you'll need to start the day in the park that you reserved. Then, at 2:00 p.m. you can "hop" to any other park, no reservations required. As long as the park isn't filled to capacity, you'll be able to enter.
If you've chosen to start your day in Magic Kingdom, but want to go to a different park first, you'll need to cancel your existing reservation for that day and switch it to the park where you want to begin.
Hope this helps. Have a magical vacation!
Diane