Opening the locking ring

WARNING: Working on fuel system.
Risk of fire! Danger of explosion!

When working on the fuel system, make sure the workstation has sufficient ventilation, e.g., by means of extraction.
Tightly seal off open lines and connections; collect any leakage fuel directly at the point of exit.
No fire, sparks, open flames or smoking.

NOTE: TECHNICAL INFORMATION
Collect and dispose of emerging fluids. Observe country-specific waste disposal regulations.

Place special tool 2 452 189 or 2 445 958 (1) on the locking ring (2).
Connect the special tool 0 495 554 (33 5 070) with a reversible 1/2 inch (3) ratchet head and place on the special tool 2 452 189 2 445 958.
Release locking ring (2) in counterclockwise direction.

Courtesy of BMW OF NORTH AMERICA, INC.