2001 Non-Bose Speaker Sizes + Installation Help?

I've searched the forum for this info with mixed results. Best guess is 6 1/2" in the front and rear, but this wasn't specific to the 2001 Cat. www.cardomain.com lists the '01 Catera as having 7" speakers in the front and rear! Can anyone confirm (for sure!!!) what the proper sizes are so I can purchase before I rip the doors apart??? Which leads me to my next question ... any "proper" procedure for getting at the speakers (i.e. door panel removal tips, methods, etc.)??