in the engine compartment, under the master cylinder along the firewall, is a linkage rod that attaches to the steering column. Follow that down to the bracket that leads to the transmission.

Loosen the bolt that locks the column rod in place. Place your shifter in park and rotate the column cover all the way to the left. Lock the bolt down and test. It may take a few tries to get it right, but when you do you will not be able to shift into reverse with the key locked, and will not be able to start except in Park and Neutral.