Check out Post #38 on the DIY Sticky for transfer case fluid DIY
I just changed my transfer case fluid last weekend. It was really straight forward. The big thing is to make sure you have a 16mm wrench, because there isn't enough room to get a socket on the fill plug.
2013 535i - ED, Oct 2012 | Cashmere Silver | Oyster/Black Nappa Anthracite | ZCW | Sirius | Air Blue 80
2008 X3 | Monaco | Sand/Black Light Poplar | ZAP | ZPP | ZCW | Xenon | Rear Fog
1988 Grand Wagoneer | Burgundy | Ghost Flames | 360 ci | Holley carb
BMW CCA #422951