Need Quick Help iPod Interface

I have a new to me 1M and want to set it up with the proper iPod interface. The car is equipped with the Harman Kardon upgrade and Serius but only has the auxiliary connector under the armrest, no USB. There is no nav in the car. I have an appointment in a few days to get the parts installed at a dealer but they called to tell me it cannot be done. Can anyone give some specific direction on the parts I need, part numbers will be great and what net result I will get with those parts. I do not need iPhone capability (though it would be a nice to have), just iPod connection and control thru the radio. Thanks much.