Where's my Body Control Module??

[Bmwtvboy]

Yesterday a local stereo shop finally figured out what all the electrical issues were; BCM. It wasn't a problem with my sound system even though a mechanic claimed it was. He said my BCM was pulling 4 amps and not going to sleep? SO, what do I do to rectify this issue? And is the alternator recharging the battery and then the BCM draining it over night? BTW, my electrical charging system(alternator/battery) checked out fine. Where is this thing? Is it expensive to replace? Repairable? How do I get it out of the X and will it require reprogramming? Thanks in advance.
Addition: Was looking up parts on Ebay and found 2 bcm's One in the right rear quarter panel with fuses and the other is a white box, but not sure where it is.