I just ran out to make sure I had it right before writing this... Here you go:
Insert key into the ignition and turn to the "ON" position.
Wait until all the warning lights and chimes turn off.
Pressing the key in toward the cylinder, turn the key to the "LOCK" position and back to the "ON" position quickly 3 times in a row. You should end with the key in the "ON" position.
Your odometer will show --------- and if you have a code, it should display after a couple of seconds... If there is no code ---done--- will be displayed.