For instructions on disconnecting the battery, see How to Disconnect a Car Battery.
If you need to remove trim that includes any knobs or drawers, remove them before trying to pry off the trim. Use your hands or a pry tool to pry off each piece of trim. Pry tools are specifically for this purpose and will not damage the trim pieces.
Disconnect components that are wired to the car. Take a picture of how each is wired for later reference.
If the stereo is held in place by screws or nuts, loosen them with the appropriate tool (screwdriver or nutdriver, respectively). If the stereo isn’t held in place by screws or nuts, you’ll need to use a radio-removal key. This tool is commonly necessary in Ford vehicles. Radio-removal keys (sometimes also referred to as radio-removal tools) will typically either be in an elongated horseshoe shape or will have a circular shape at one end and a notched shaft at the other. They’re available at most auto-parts stores. Insert the keys into the two small slots in the face of the stereo. You will release a mechanism holding the stereo in place. Slide the radio-removal keys into each slot again until you feel the stereo loosen from in its housing. You should then be able to pull out the stereo relatively easily.
First unplug the antenna wire, which will typically be a thicker wire plugged in separately from the rest. Once it’s unplugged, you should be able to move the stereo around more freely. Next unplug the each of the wire harness connectors. There will typically be several of these and you can recognize them because a series of wires will feed into each one. The plastic piece into which the wires are fed should have either a tab or a button you can push, which will release the harness.
To be safe, check the wiring diagrams for both your car and the new stereo to verify you’ve connected them correctly. If your car’s stereo doesn’t use wire harnesses, you’ll need to match up each wire manually. The wires are color-coded; however, the wires on an after-market stereo may not match with the color-coded wires in your vehicle. It’s best to study and follow the wiring diagram that came with the stereo. Connect the matched wires. There are two options for connecting the wires, crimping or soldering. Crimping is faster and easier, but soldering will provide a more stable and secure connection. Be sure to use the proper size crimper and don’t try to bundle the wires with tape — it will eventually dry out and fall off. Bundle wires using zip ties instead. [6] X Research source
Push down on the tabs located around the metal sleeve with a screwdriver to secure the metal sleeve in place.
If you aren’t using a wiring harnesses, you’ll need to manually connect the power. Determine whether your car has a switched power source (typically a red wire) or a constant power source (typically a yellow wire). Some vehicles even have both types of power sources. For more information on switched versus constant power, go here.
If you aren’t using a wiring harness, you’ll need to locate the bolt, wire, or screw that connects with the car’s bare metal chassis. Loosen the bolt, wire, or screw and slip the stereo’s ground wire (usually black) underneath, then tighten. Note that the ground connection is important to the optimal performance of the stereo. If the ground wire doesn’t connect to the bare metal, it won’t work. And if the ground wire connection is loose, it could result in poor audio output. Sand down the area with sand paper to ensure a good connection.
