everyone always says unplug the battery for a while (which works) but here is what an fsm thingy says. it's from www.alldatadiy.com. that website is awesome! you can get the fsm for 24.95 a year and they update it 4 times a year if neccesary. you can get additional cars for 14.95 after the the first one.

1. Turn the ignition key on.
2. Turn the diagnostic mode selector on the ECU fully clockwise until both diodes flash 4 times then turn the selector fully counterclockwise. The ECCS system is now in mode 4.
3. Turn the ignition key off. This will return the ECCS system to mode #1 (normal operating mode). ECU memory is now erased.

 

according to http://www.brianv.net/mods/ecu/ you have to do this twice to reset the ecu.

Summary of how to reset:

Turn screw clockwise until it won't turn any longer.
Wait 5 seconds
Return screw counter-clockwise until won't turn any longer.
Wait 5 seconds
Turn screw clockwsie again until it won't turn any longer
Wait 5 seconds
Turn screw counter-clockwise again until it won't turn any longer
ECU should be reset now

and of course turning the ignition to the 'on' position when starting and 'off' when finished.

 

both ways probably work tho

 

yeah, this may be a litle quicker. i've heard many different times and the shortest time i've heard is 15 minutes which is still slower than this way.