The starter motor on a 1996 Nissan Pathfinder is located on the
bottom of the engine block, generally on the
passenger side (right side). You'll need to get underneath the vehicle to access it. It's usually fairly close to the transmission bellhousing.
However, the exact position can vary slightly depending on the engine (VG33E or KA24E). A repair manual specific to your Pathfinder's engine would give you the most precise location.