If you do a search, I'm sure you can find a link that has step by step instructions with pictures, but I'll give you a brief description:

1.) Remove your passenger side kick panel (on side of car under glove box)

2.) Find the OBD-II plug (its a little rubber piece with a harness with two wires in it)

3.) Bend a paperclip into a "U" shape and jump the two wires together or even better, use one of those "Y" shaped grounding connectors that you can get at radio shack:


4.) Turn the key to the second on position, and count the number of flashes.