WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata, 2004 Mazda MX-5 Miata, and 2003 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.
Insert the key into the timing belt pulley, facing the tapered side downward. Push the key until it stops.