Hope this helps:
Removing and installing/sealing cylinder head cover (N57 D30 U/O/T 0/1)
When working on the oil, coolant or fuel circuit, you must protect the alternator against contamination.
Cover alternator with suitable materials.
Necessary preliminary work:
Remove intake plenum.
Remove all injectors.
Remove pressure accumulator.
Release engine wiring harness in area of cylinder head cover.
Release screws (1).
Lay cable clip (2) to one side.
Release screw (1).
Turn oil filler neck (2) in direction of arrow to stop.
Lift out oil filler neck (2).
Press locking hooks (1) down.
Remove hose (2) for engine ventilation.
Undo cylinder head cover bolts in the sequence 23 to 1.
Replace profile seals (1 and 2).
Install cylinder head cover with new profile seal.
Secure cylinder head cover bolts in the sequence 1 to 23.
Tightening torque: 9Nm