With Fuel Pressure Gauge
WARNING: This page is about a different car, the 2002 Mazda Tribute, 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
Remove fuel tank cap to release fuel tank pressure. Connect Fuel Pressure Gauge (T80L-9974-B) to pressure relief valve (Schrader valve) located on fuel injection manifold rail. Using a suitable container, open fuel valve slowly and drain fuel in container.