First, de-pressurize the fuel system and equalize tank pressure by removing the fuel filler cap or depressing the filler flap where necessary, and unconnection cable of the negative battery terminal. On four-cylinder models since 2008, take off the air intake duct, cut off the accelerator cable to the throttle lever cam, and, as fitted, the cruise control cable too. Go on to disconnect the fuel supply line to the fuel rail, the vacuum line to the fuel pulsation damper and the electrical connectors to the fuel injectors. Unscrew the fuel rail mounting bolts and loosen the fuel rail together with the injectors. Lift the clamp that attaches the fuel injector to the fuel rail and withdraw the injector, make sure to remove the old O-rings and replace them with new ones and then reassemble again. Installing is the opposite of de-installing, lubricating the new injector O-rings with clean engine oil and tightening the fuel rail mounting bolts to a given torque. Once the battery has been reconnected, the Powertrain Control Module will have to relearn the idle and fuel trim strategy to work optimally and then the engine can be started with the purpose of verifying that no fuel is leaking. In V6s, take out the upper intake manifold, unscrew the vacuum line and fuel supply line, and electrical connector(s) of the injectors, in one piece, lift the fuel rail and injectors. The same thing applies to the 2009 through 2012 models (following the same steps), except, to disconnect the fuel supply line at the quick-disconnect fitting and remove wiring at each fuel injector. In 2013 and subsequent models, unconnect the negative battery cable, loosen the engine cover and unconnect different parts and then unscrew the fuel rail and injectors. Install O-rings and Teflon seals when needed and be sure to install properly without lubricating the Teflon rings. Lastly, carefully tighten all fasteners to the required torque and look after leakages after reconnecting the fuel system.