Does anyone know where I can find documentation/Instructions/Illustrations or a DIY on removing the headliner as well as information on cab top hardware for adjustments on a 997.1 C4S?

During my ownership history, I've brought it in twice to hve rattles/squeaks resolved and after a year the noises return. So would like to know how to resolve myself.

 

Read this:
https://www.6speedonline.com/forums/...f-rattles.html

This shop manual will give you info on the 996 top & it should be close enough:http://cannell.co.uk/Manuals.htm

 

AWESOME! This is exactly what I was looking for. Thank you.

Several tiny squeaks and rattles are driving me nuts...

 

This may also help you:
The Parts Catalog (downloadable PDF file) is on the Porsche.Com website.
Go to "Personalization & Service" then "Porsche Service" then "Parts and Diagnostic Information" then "Porsche Original Parts Catalogue". You can then select the model you want to view.