You'll need to take out the dash and drill out the pin as in part 14. It's a pretty awkward position to drill but it can be done. Several of us have done it. Took me about 3 drill bits too.

Picture from step 14 linked below the pin itself is just to the left of the key cylinder. It prevents the ignition from twisting out.
http://chevelle.cvpo.com/Resized%20C...te/Xfire15.jpg