Fuel Pressure Release
WARNING: This page is about a different car, the 2001 Jaguar XKR, 2001 Jaguar XK8, 2001 Jaguar XJR, 2001 Jaguar XJ8, and 2001 Jaguar S-Type. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Locate service valve in fuel line, in engine compartment. Connect a suitable hose to service valve. Release fuel pressure by opening service valve and draining fuel into a suitable container.