Connect the RCA ends of the cable to the "AUX IN" or "CD IN" jacks on the back of the computer. Plug the black, or white, connector into the white, or left jack, and the red connector into the red, or right jack next.
Plug the 1/8-inch mini plug into your MP3 player's "Headphone Out" jack, then play an audio selection. Keep the volume at a minimum until you have completed all of the steps in this tutorial, then increase it to taste.
Power on the stereo by pressing its "Power" button, then press the "Source" button until either "Aux" or "CD" appears on its screen. The source you select will depend on the input jack that you plugged the RCA cables into. Increase the volume on the stereo to taste.