WARNING: This page is about a different car, the 2006 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Outer Sill Service Joint (King Cab) (1 Of 3)
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Identifying Outer Sill Service Joint (King Cab) (2 Of 3)
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Identifying Outer Sill Service Joint (King Cab) (3 Of 3)