[AnemicOak]

You say your friend had his book created in PDF, does he still have the original file that was used to create the PDF (Word doc or whatever it was)? That would generally be a better starting point than a PDF. It would probably also help to know if this is a regular fiction or innear non-fiction book that lends itself to reflowable formats or if it was originally done as a PDF because it's better suited to a fixed format.