If I remember correctly this link has the same pics/diagrams from the GM manual.
http://www.justanswer.com/pontiac/5m...eatercore.html
It's nice to have the locations of the screws which these point to. Depending on your physical size, you might be able to get at the core from both driver and passenger footwells without removing anything else.
About the hardest part is sneaking the cowl out of the underseat duct work run, right below the radio.
The 2 hose clamps inside the engine bay gave me a struggle, or than that not bad.
