To remove the fuel system, start by relieving the fuel system pressure and equalizing the tank pressure by removing the fuel filler cap. Disconnect the cable from the negative battery terminal and remove the air intake duct on four-cylinder models or the upper intake manifold on V6 models. Disconnect all interfering wiring, including the connectors at each fuel injector, and move the harnesses out of the way. Remove the fuel supply line from the fuel rail and remove the old o-rings, as well as the fuel rail mounting bolts. Remove the fuel rail and injectors as a single assembly, ensuring no o-rings remain in the injector holes. Remove the retainer securing each fuel injector to the fuel rail and pull out the injector, and install new o-rings to the injector.