Simon,
Ignore the 'how to' regarding the magnet.
When you look in your car, look where your right foot goes. There is a trim panel that will extend from your right foot up towards your knee area.
On this trim panel, there is a vent. The vent has a cam-locking 'screw' in it. If you turn this screw 1/4-1/2 turn counter clockwise, it will come loose. You do not remove the screw all the way. When you turn it 1/4-1/2 turn, it comes loose, and the vent should come off.
Behind this little vent is another screw (zinc/gold colored phillips head). Remove this screw. Now the trim panel can be removed.
You have to flex the trim panel a bit to get it out. This is the hardest part of the removal/install, but still very simple. Just be careful not to over stress it. A little bit of slight flex will suffice.
Once it is out, lay down into your floor board as much as possible. You will see wires connecting to the back side of the gas pedal. A small headlamp or flashlight will help here. These wires connect to the TPS. There is one plug that has a 'push tab' on each side. So, you basically have to get your hand on this plug with your pointer finger and your thumb. Depress the tabs on each side and pull the plug out. BE SURE to depress those tabs. If they are depressed, you should be able to pull the plug out without much force. After it is disconnected, you simply install the sprint-booster in it's place, and connect the factory wire to the end of the sprint booster. Basically, the sprint booster is mounted in-between the existing original wiring.
Re-install the factory plastic panel - re-install the screw - re-install the vent - re-tighten the cam-locking screw.
Done!
This literally took me less than 3 minutes. I am not a small guy, but not a huge guy either (5'11" 185 lbs), and I have rather large hands. I didn't have any trouble. If you are not able to get down on the floor board very well, or your hands are too large to maneuver the electrical plug, find a small child who can take directions well.
I did not unplug my battery and 'reset' my ECU. Some people say they had to. Mine worked just fine without doing this...
I also went with the 451A (not the A2), and it doesn't seem overly aggressive at all. I'm anxious to see how you like the A2.
Tools needed - Phillips Screwdriver
Optional - small light source
Time to change - under 15 mins
Difficulty - 1 out of 5
SQ