04 grand cherokee radio w/ new amp

I need instructions on how to add an aftermarket amp and subs to a factory Infinity system and head unit in an 04 Jeep Grand Cherokee. its got the factory 10 disc CD changer as well.

Thanks

The factory amplifier is located under the rear passenger seat.  You can tap the rear speaker wires there and connect your LOC, then run rca's to the amp.  Or, you can just tap those wires and run them to the high level input on your amp.  Good Luck!