You don't need to entirely remove the radio for that.

Remove the center console and piece under the radio. Then, just look behind the radio for the serial number. It is stamped right on the back. If you want to remove it completely, you will need very tiny asian hands to get a screwdriver back there to get the two mounting screws off. Then you will need to pull the harnesses and antenna cable out and remove the radio.

It is much easier to just get it exposed enough to read the serial number. I am sure that you could just look back there with a flashlight and see the serial number.