All you need to do is turn a screw near the throttle body on the intake manifold. I dont remember if its counter clockwise increases the idle while clockwise decreases it. Just try both ways and see.
Heres a pic. The red circle shows the which screw it is. It will require a flat head screw driver.
Sorry this was the only pic i could find. Ill take better pics tommorow if you need it. It is to the left of the red hose thats on the throttle body.