Put the key in.
Turn it to the ON position, or whatever one is before actually cranking the motor.
Press and hold the button for 3 seconds. Blue or green button, under the driver side dash. Should be around where your right knee would be.
Here's a pic of the reset button in my '95. Unplugged, panel removed to take the pic.
1. Insert key into ignition, turn keys 2 clicks (don't start the car).
2. Push and hold reset button for a few seconds until Maintenance Req'd light goes out.
3. Release reset button, turn off ignition, and you're done.