Fuel inertia (shut off) switch

I have a 1996 Ford F150 XLT. I need to change the fuel filter but can't find the fuel shut off switch to relieve pressure in the fuel line. My Haynes manuel shows it to the left of the brake pedal in the fire wall but it's not there. Any suggestions?

It should be there, high up, just above and to the left of the steering column. Its encased in somewhat of a cage, with just enough of an opening at the top to allow you to press the button for reset.

You don't need to mess with the inertia switch. All you should do is to remove the plastic "valve stem cap" on the fuel rail and using a rag to keep the mess to a minimum, depress the core to relieve the pressure. Then you can simply replace the fuel filter.