How do you replace fuel return valvs on 85 85 Jaguar XJ6?

To replace the fuel return valves on an 1985 Jaguar XJ6, first ensure the vehicle is off and the fuel system is depressurized. Remove any necessary covers to access the fuel rail, then disconnect the fuel lines from the return valves. Unscrew and replace the old valves with new ones, ensuring they are properly seated and sealed. Reconnect the fuel lines, check for leaks, and start the engine to ensure proper operation.