[DiapDealer]

There are no step-by-step instructions/details for turning a PDF into anything else. If you can avoid doing it at all, you should by all means (meaning start with ANY source OTHER than PDF). If you can't avoid it, you're just going to have to find what works best for you (for THAT particular PDF)... they're all different, and they're all a PITA.

But mainly... Sigil just doesn't bring anything special/helpful to this particular task (except for polishing the earlier PITA stuff).