Chrysler-Jeep Cherokee

[Hierro]

hi all,
i've a 98 jeep cherokee with factory dash stereo am/fm & cassette, and no
cd changer.
i'd like to use the line in of cd changer for using my small mp3 player in
my car, but the stereo says:NO CD; anyone has a wiring diagrams of the 8 pin
din connectors to cdchanger, or has any tricks to make usable that line
in????

thanks in advice!