Help creating book from existing epub and m4b files

[seannymurrs]

I'm trying to use syncabook to create a read aloud epub. I already have an epub copy of the book as well as an m4b copy of the audiobook. From looking at the direcctions, it seems like I need the ebook in xhtml format. I know I can get the xhtml files from the epub (by renaming the epub to a zip and extracting the xhtml files). Can I use those xhtml files to sync the book, or do I need to convert the epub to a txt file and then use syncabook to convert the txt to xhtml? If I can use the xhtml files from the epub, should I manually separate them into sync_text and no_sync_text folders?