The main source of entertainment for most drivers is their music. Through the years, the way people listen to music has changed dramatically. For this reason, standard vehicle equipment does not always match the latest media technology taking the world by storm. If you find yourself in the situation where you can’t play your music through your stereo, fear not. You can upgrade your stereo technology with relatively little hassle.



Select the replacement head unit. You can obtain an mp3 and WMA player from for as little as $89. The most important features are the ability to play mp3 and WMA format files burnt on a CD but also from a USB drive (thumb drive or removable hard drive). Another important thing to consider when upgrading your head unit is what aftermarket unit will fit best.
Head units come in three sizes – Single DIN, DIN and a half, and Double DIN. If your unit is Single DIN it will likely be compatible with most aftermarket head units. Otherwise you may need a mounting kit for your vehicle.[1]
Get a wiring harness or adaptor. This will allow the car radio wiring to plug into the back of the new radio. These can sometimes be found for $4.99. Make sure that the plug is compatible with your car (check the list on the back of the box).
Connect your new radio to the wiring harness. Twist the correct wires together and then solder them (or use wire nuts if you do not have soldering equipment). Cover the exposed wire with electricians tape or heat seal tape.Remove the factory installed radio. This will likely consist of having to pry away a plastic cover panel on the front of the radio and take out two screws. This will then allow you to slide the radio out of the dash. If you are unsure how your radio comes out, you should consult a service manual for your specific model.
Remove the antenna wire from the back of the radio. This will be easily done once you slide the radio head out of the dash.
Remove the wiring harness plugs. These plugs go to the back of the radio and can be released by pressing the release tab and pulling out.
Remove any mounting brackets. If the sides of the radio have mounting brackets, remove them from the factory radio. make sure that you mark which one goes to the left of the radio and which one to the right.
Plug the wiring harness adaptor into the wiring harness. This will allow you to fit your wiring harness to your new aftermarket stereo head.
Plug the other end of the wiring harness adaptor into the radio. There is a place on the back of the radio head for a plug. That is where you will plug the adaptor in.
Plug in the antenna wire. Do not forget to plug the antenna wire into the large round hole in the back of the radio head. This will allow you to pick up AM/FM station
Test the radio. Be sure that you can hear sound through the speakers. See if the radio lights come on. This indicates that power is getting to the radio. Also confirm that the antenna is plugged in properly by tuning to different FM and AM stations.
Slide radio into the head unit slot. Mount the new radio with the same screws as you took out of the old head unit, unless you had to use a mounting adapter. Now you have installed your new stereo head unit
For most Toyota models, including Corolla, you will need to use a dash install kit for single or double DIN stereos.[5]
Reinstall any panels or pieces of dash that were removed. This step varies by model, so be sure to consult your service manual if you are unsure about how to proceed.
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