What is the proper installation procedure of the driver's side airbag? Thanx in advance.

You may want a dealer to install this as there are things of importance related to the function of the air bag. 1. that it opens. 2. there is a code that has to be set. 3 you don't want it to open-up during installation.
there expensive, even recycle yards are not
cheap.

There's a separate SRS module that may have to be replaced if the airbag deployed. I don't know specifically about the Aurora, but it was that way in another car I rebuilt for fun and profit, a 94 Chevy Lumina with the 3.4L- talk about a tight fit for an engine.