How can I hook up an Ipod / MP3 player to my 2003 Hyundai Tiburon factory stereo head unit?

I have the original Infinity stereo and it has a round 8 pin outlet on the back which is for a CD changer. I believe there is a cable that can be plugged in there and connected to an MP3 player. Has anyone done this and can you show me which cable / adapter will work? Thank you in advance