Remove the Lambda oxygen sensor and the monitoring oxygen sensor for cylinders 5 to 8

• Unlock connector (1) and detach.
• Loosen the cables from the clamps.
• Release and remove the control sensor (2) with the special tool.
• Unlock connector (3) and remove.
• Loosen the cables from the clamps (4).
• Release and remove the monitoring oxygen sensor (5) using special tool.

Courtesy of BMW OF NORTH AMERICA, INC.