The tail lights on my 1999 Lincoln Towncar do.

The tail lights on my 1999 Lincoln Towncar do not come on when the headlights come on. The garage diagnosed the problem to be the lighting control module (LCM) needing replaced. They want $830 for the part plus labor. I can get a remanufactured part for under $300, the problem is the repair manual doesn't mention this part or say where its located in the car. Can you tell me where the LCM part is located and how to replace it.

Thank you,
KZ