Mine was a 2001 SOHC, assuming yours looks the same, don't just try to pull the valve off the hose. there's a plastic clip/clamp that holds the PCV valve in the hose and supports it. i refer to these kind of clips as "ratchet style" in that they have interlocking opposing teeth. to release them you have to disengage the teeth. i find a small screw driver works best to accomplish this. even with the clip disconnected the valve can be very difficult to remove, as the old rubber hose tends to become stiff.
i also found it easier to disconnect the 2 smaller hoses from the intake manifold before removing the valve. mine had a plastic "T" fitting, which i had to remove from the top of the PCV valve and reuse. it's best to buy a Motorcraft brand PCV valve, as cheap valves can make noise and the plastic "T" fitting fits better on the Motorcraft valve.
