Thanks to all that have weighed in! I am not sure what caused the local mechanic to speculate about the tank removal. I guess several more recent domestic vehicles are so designed.
A friend directed me to YouTube where there were an astonishing volume of videos on just this topic. None that I saw involved a 940 but I suspect that little had changed between models (240 etc)I found. The Turbo apparently makes no difference. The 240 wagon video I watched was made by a well spoken young guy that seemed to have some experience. Another video was made by a fellow that had obvious Volvo supplied tools. A gizmo designed for the removal of the securing ring at the top in particular. It clearly made his process easier but surely added to the expense. That didn't seem reasonable for a tool that I would likely never use again!
The detailed instructions supplied by you Brickboard guys will be a big help. The 240 video made the process seem almost identical to the Saab 900 pump that I changed out some years ago. That helps instill confidence in the likes of me. (Decidedly non mechanic)
Thanks again!
Barrelhouse