If you jump the resistor connector (harness side), the fuel pump will run at a constant 12V...this is very easy to do. You keep the old wiring though.
The other variations of the "12 Volt Mod" are replacing the wires all the way to the pump with 10GA wire and using a relay in the rear of the car, (activated by the old stock wiring) to provide a 12 volt source straight from the battery. Advantage is low voltage drop.
The question is why do you want to do this? The only advantage with running the pump at 12V is a constant speed/output...it makes tuning easier. Or, if the resistor is causing problems producing a constant output at 9V....old, brittle wiring is another good reason. On a stock system, there is no real advantage and you will wear the pump out faster.