Necessary preliminary tasks:

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2006 BMW X5, 2006 BMW X3, 2005 BMW X5, 2005 BMW X3, and 2004 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Secure engine in installation position, refer to SECURING ENGINE WITH SPECIAL TOOL IN INSTALLATION POSITION (M54) .
Remove reinforcement plate
Remove complete exhaust system, refer to 18 00 020 REMOVING AND INSTALLING COMPLETE EXHAUST SYSTEM (M54) .
Detach grounding cable from body.
Remove right engine support arm with engine mount, refer to 22 11 100 REPLACING RIGHT ENGINE SUPPORT ARM
Remove air pump

NOTE: The oxygen sensors are in danger of being damaged when the exhaust manifolds are removed and installed.

Remove front control sensor. Refer to 11 78 511 REPLACING OXYGEN CONTROL SENSOR (CYLINDERS 1-3) .

Remove cover from fuel injectors.

NOTE: Do not mix up monitor sensors for cylinders 1 to 3 and 4 to 6 at plug connection to wiring harness.

Mark plug connections.

Fig 1: Locating Monitor Sensors

Courtesy of BMW OF NORTH AMERICA, INC.

Unclip cable from holder. Disconnect plug connection. Unclip cable on rear side of engine from cable guide.

Remove monitor sensor from cylinders 1 to 3. Refer to 11 78 611 REPLACING OXYGEN MONITOR SENSOR (CYLINDERS 1-3) .

Unscrew nuts.

Fig 2: Removing Exhaust Manifold

Courtesy of BMW OF NORTH AMERICA, INC.

Remove exhaust manifold (1).

Installation:

Clean sealing faces, replace gaskets.

Replace nuts.

Tightening torque 11 62 1AZ. Refer to ENGINE - TIGHTENING TORQUES .