The preferred method of resetting the ECU involves pulling the fuse in the underhood fuse box marked BACK UP for 15 seconds and then replacing it.

The absolute best way to do it is while the car is cold, turn the key to the on position so you can turn off all of your accessories (stereo, ventilation, etc). Then turn the key off and pull the fuse. After you put the fuse back in, start the car up and let it idle until it comes up to temp, being careful not to turn on any accessories or step on any pedals.