DIN is a unit of measurement used for car stereo head unit (in-dash receiver/players). DIN generally refers to a single DIN, which is 180 by 50 millimetres in size. A double DIN is 180 by 100 millimetres in size. Different car manufacturers use different sizes depending on the make and model of the vehicle. Since the single DIN is smaller than the double DIN, a mounting bracket is needed in order to fill up the extra space in the console. These brackets can be purchased for less than £6 at car stereo stores.
Disconnect the car's battery. This will prevent any shorts.
Remove the dash panel to access the radio. Pry off the dash using a flathead screwdriver. Insert the screwdriver between the dash and radio and gently pry off the dash panel. This will expose the radio fully.
Unscrew the double DIN radio using the flathead screwdriver or a wrench. Pull it out, and disconnect the wires attached to it.
Insert the single DIN head unit into the mounting bracket. It should easily fit right in. The instruction booklet for the mounting bracket will give exact specifications for the particular bracket model.
Connect the vehicle's wires or wiring harness to the new single DIN head-unit. Insert the new head unit with mounting brackets into the car's dashboard. Screw in the mounting bracket using the screws from the old head unit. Replace the dash panel. Reconnect the car's battery, and turn on the vehicle.