Welcome to planDisney, Glenn! We are glad you brought your question to us.
I'm sorry to hear your son can no longer join you on your visit to
Magic Kingdom Park. As you know, at this time Guests who wish to visit a theme park must have a
Disney Park Pass reservation as well as valid
admission. The reservations you made are connected to the Guests you selected when you created your party. Your son's reservation cannot be transferred to someone else.
However, no worries! You may simply cancel your son's Disney Park Pass reservation and make a separate reservation for the person that will be joining you. (Subject to
Disney Park Pass availability.) It is not necessary for everyone to be on the same reservation. As long as everyone has admission and a Disney Park Pass reservation for the same theme park on the same day, you will all be able to enter the park together.
Disney Park Pass reservations can be canceled in
My Disney Experience under "My Plans" (or "Future Plans" in the My Disney Experience mobile app.) When you select "Cancel Reservation", on the next page you'll be able to select which Guests you wish to remove from the reservation.
I hope that helps! Glenn, if you have any additional questions about Disney Park Pass reservations or visiting Walt Disney World Resort, please feel free to write us back. Enjoy your visit to "The Most Magical Place on Earth"!
Anne Marie