Where is the fuel pump wiring harness located? Is that the best thing to dissconect to allow the engine to reliev the pressure?

 

the easiest way would be to hook a vacuum pump up to the fuel pressure regulator and suck it up so that the pressure bleeds back to the tank, or like you said, unplug the harness or pull the fuel pump fuse and attempt to start the engine to let off pressure

 

That's the way most people do it. That's how I did it on my PU, but managed to pull a little too hard and one of the fuel lines that was rusted through broke off, which was actually a good thing that it happend in my drive way.

 

On my 93 4Runner ther's a small access panel under the rear passenger side seat, undo 2 or 3 screws and you can disconnect the fuel pump wiring there. If you do it while the engine is running most of the pressure is relieved.