Move the Odyssey's gear selector to Neutral, turn the engine off then set the parking brake for safety.
Open the hood and unhook the negative battery cable with the pliers.
Open the glove box door. Grasp the A/C control panel beneath the radio. Pull the panel sharply to unhook it from the dash. Unplug the connection from behind the panel then set it aside.
Remove the three Phillips head screws that secure the changer. Two are directly beneath the radio; the other one is between the two air vents.
Pull the CD changer out of the dash. Unplug the factory wiring harness and the antenna cable.