Any luck with this yet? We have thorough SOPs that you could maybe look at for ideas. However, you are right that the content would need to be replaced in its entirety. Some questions to ask before you get too far:
1) Must the manual describe dummy-proof steps and settings, or more general terms? Is it to be used as a step by step guide for new techs?
2) Should the manual avoid command/tool specifics in order to remain relevant with software changes? That is, are conceptual steps or detailed tool settings more important for this document?
3) Is project history or context relevant to the document? A user who needs to know the big picture will call for more information that is not part of processing steps.
Other things are sure to be included, such as layers, field definitions, and the like.
