How do you change a fuel injector on a 2005 BMW x3?

To change a fuel injector on a 2005 BMW X3, first disconnect the battery and relieve the fuel system pressure. Remove the engine cover and intake manifold to access the fuel rail. Disconnect the fuel rail from the injector, remove the old injector, and install the new one with a new O-ring. Finally, reassemble the fuel rail and intake manifold, and reconnect the battery.