Extension Tube Replacement

Drain engine oil.
Ply out the extension tube from the engine oil sump.

Fig 1: Plying Out Extension Tube From Engine Oil Sump
Courtesy of NISSAN MOTOR CO., U.S.A.
Remove the O-rings from the extension tube and replace them with new ones.
Apply grease to the new extension tube O-rings.

Fig 2: Identifying Extension Tube O-Rings
Courtesy of NISSAN MOTOR CO., U.S.A.
Install the extension tube into the engine oil sumps.

Fig 3: Installing Extension Tube Into Engine Oil Sump
Courtesy of NISSAN MOTOR CO., U.S.A.