Where is the transmission fill plug?
 

Have you wondered, done a search and found nothing? Here is to help you out.

The fill plug on a 2006 BMW 530xi AWD is at the left rear corner of the transmission, 1 inch above the gasket line. It is obscured totally by the coupling drive shaft from the gear box to the front 2 wheels. It needs 8mm allen socket. In order to get access to this plug, you need to remove the 4 torx bolts and let the coupling gear hang down.

A picture says a thousand words.

hey, i been trying to tackle this last week with no luck, and thought it was a stealer job only, i obviously came back with 860+ quote. I still would like to do this myself, could you tell me if you need a impact to remove the drive shaft screw for the front wheels.

No impact is needed. You need a set of torx sockets, and some wobble extensions. The four torx bolts are not on there that tight. Remove one end and let it hang down.