From a secret guide that a friend gave me.... this is for the 06-07 Explorer...
1 Disconnect the negative battery terminal to prevent an accidental short circuit.
2 Open center console and remove (2) Phillips screws then unclip and remove entire panel surrounding shifter.
3 Remove dash panel surrounding radio to access the factory radio screws.
4 Remove (4) 9/32” screws to remove the factory radio.
The mounting kit number from Metra is 99-5807.