WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Water Pump Components For Removal Or Installation
Courtesy of NISSAN MOTOR CO., U.S.A.
WARNING:
Never remove radiator cap when engine is hot. Serious burns could occur from high pressure fluid escaping from radiator.