Please help with adding an aux port
 

Hello, I have a 1997 chevy lumina car and I want to put an aux port into it so I can play my music, but I don't know exactly how to do that. I have watched many videos online and I vaguely get the idea but I don't know anything specific so I would rather not risk it on my car and destroy my radio. It has the factory Delco radio in it with the tape player (but the tape player doesn't work). I have heard about running lines directly to the board, I have heard about using the extra pins on the back from the cd changer slot that I don't have installed (the preferred method if possible). I have the radio wiring diagram here from modifiedlife.com:

1997 Chevrolet Lumina Car Stereo Radio Wiring Diagram
Radio Constant 12V+ Wire: Orange
Radio Ignition Switched 12V+ Wire: Yellow
Radio Ground Wire: Black/White
Radio Illumination Wire: Gray/Black
Radio Dimmer Wire: Brown/White
Radio Antenna Trigger Wire: N/A
Radio Amplifier Trigger Wire: N/A
Front Speakers Size: 5 1/4″ Speakers
Front Speakers Location: Doors
Left Front Speaker Wire (+): Tan
Left Front Speaker Wire (-): Gray
Right Front Speaker Wire (+): Light Green
Right Front Speaker Wire (-): Dark Green
Rear Speakers Size: 6″ x 9″ Speakers
Rear Speakers Location: Rear Deck
Left Rear Speaker Wire (+): Brown
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Dark Blue
Right Rear Speaker Wire (-): Light Blue

Any help would be greatly appreciated! Thank you!