Raise the vehicle and support it safely. Remove the splash guard under the engine and the front end reinforcement if applicable. Remove the exhaust system and exhaust heat shields, along with any support brackets for heat and splash shields as needed. At the transfer case, use paint to match mark the front driveshaft flanges and remove the front driveshaft from the transfer case output flange, tying it to the side. Exercise caution when removing the driveshaft from the transfer case flange; gently tap the driveshaft flange to loosen it, as it is a slip fit and oil loss can occur if pulled out. At the transfer case output flange, match mark the rear driveshaft flex-disc flanges with paint, then remove the three bolts holding the flex disc to the transfer case flange and discard the old fasteners. Remove the driveshaft center bearing support fasteners and lower the center of the driveshaft sufficiently to disengage the flex-disc from the transfer case flange, tying the driveshaft to the side. To prevent damage to the rear driveshaft CV joint, do not allow the driveshaft to hang down unsupported. Support the transmission from below using a transmission jack, then remove the mounting fasteners for the transfer cross member and take out the cross member. Disconnect the xDrive servo motor and resistor electrical harnesses. While supporting the transfer case, remove the mounting bolts and lower the transfer case. When installing, inspect the dowel sleeves and replace them if damaged, transfer covers and protective caps to the new transfer case as applicable, and replace the transfer case input shaft sealing O-ring if needed. Apply a thin coat of Weicon® anti-seize grease to the dowel pin and input shaft splines. Do not reuse ZNS fasteners, as they are designed for one-time use only. After completing the work, check and top off the fluid level, then drive the vehicle approximately 200 meters (600 ft) and recheck the fluid level. If new parts were installed, use the BMW diagnostic tool to carry out the transfer case adaptation reset.