Remove the ashtray and find two screws that hold the bezel in place. Remove the two screws . Gently pry the bezel from around the radio. It's plastic and will break easily. Four screws will be exposed you will need to remove to take out the radio. Unplug the wires.
If you have never done this before or do not have the proper tools, seek help from a professional to avoid damage to the plastic bezel and the radio wiring.