Found a video on Youtube for the E53 TC rebuild,
https://www.youtube.com/watch?v=FbZmmOphYw0&t=163s
The ATC700 for the E70 is not much different here is the list of changes
Transfer Box ATC700
The transfer box ATC700 is a further development of the ATC500 that was fitted in the
E53. The power is output via a chain to the propeller shaft to the front axle and apportioned
by a multi-disc clutch.
The torque transmission efficiency of the multi-disc package has remained the same
compared to the ATC500.
Only slight changes have been made compared to the ATC500.
• Installation position of coding resistor
• Optimized lifetime gear oil
• New ventilation system
• Transfer box control unit (VGSG).

Here is another video of interest

https://www.youtube.com/watch?v=TivwD8MTMWg&t=12s