The buttons that allow the headrests to be removed appear when the headrests are installed.
Also, what psfred meant was that when you fold the middle row seat, you'd need to remove those headrests to allow the seatback to fit flat. Typically the headrests are removed and stored in the holes located at the rear of the seatcushions, which come to the top of the seat cushion when they are lifted forward.
Hope this helps
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car