Remove the covers to your 1997 radio speakers. Remove the radio speaker retaining screws. Remove the wiring harness from the back of the radio speakers. Reverse the process to install your new radio speakers.
See http://www.miata.net/garage/miata_radio_removal.html
Remove the 1993 Toyota decorative radio cover in. Remove the radio retaining screws. Pull the radio out. Remove the wiring harness.
Remove the decorative radio cover. Remove the radio retaining screws. Slide the radio out. Remove the wiring harness from the back of the radio.
Push the volume knob to turn on and off. Everything else is pretty standard.
with a crowbar
All of the fuses in the miata are located in the engine compartment. Looking at the car from the front, there is a black case near the left hood hinge. Open it, and the radio fuse is in there.
no
Hold the 'clock' button until it starts to blink, adjust the time and poke the 'clock' button to accept the time.
Remove ashtray and carefully pry off the surrounding trim. Also pry off the trim around the radio. You will see the screws that hold the radio in (4 i think). Unscrew and you are done.
Look closely at the radio and you will find two small, plastic tabs on either side of the radio. These can be lightly pried off with your fingertips or a small flathead screwdriver. Careful not to mar your radio bezel. Once removed the radio can be removed with your typical Ford-style radio removal tools purchased at any auto shop.
It is not difficult. First you have to remove the 12vot cigarette lighter plastic and then remove the radio. 4 screws for the radio. Then you have to remove the panel that goes from the radio up to the instrument cluster. This panel has 4 screws. 2 of them are on top of the instrument cluster (visible) and the other two should be visible after removal of radio.