Harry,
that "special tool" is a standard magnet. I used the back off an old speaker, but any decent magnet wiil work.
Here's the proceedure:
Turn the car on ACC power.
Hold down the lock and unlock buttons on the FOB for about 10 seconds, until the horn sounds. This puts it in reset mode.
Hold the magnet over the valve stem of the LEFT FRONT wheel, until the horn sounds.
Repeat at the RIGHT FRONT, horn will sound, RIGHT REAR, horn will sound, and last the LEFT REAR, horn will sound TWICE if all done correct.
That's it....you're done!
one other thing....you're on a time limit....I think it's about 10 seconds to get from wheel to wheel