Relieve fuel pressure, then remove
Fuel Tank (Frontier/Xterra) or rear seat/access cover (Pathfinder). Disconnect electrical connector, detach fuel feed/return lines, remove fuel pump/sending unit mounting screws. Disconnect fuel pump electrical connector, disconnect fuel hose, depress locking pawl and separate fuel pump/bracket from sending unit. Check strainer for contamination, replace if necessary. Clean fuel pump/tank mounting surfaces, position new 0-ring, guide fuel pump/sending unit into tank. Tighten mounting screws, connect fuel lines, connect electrical connector (Pathfinder/Xterra). Install access cover/rear seat/fuel tank.