As Vic says, once DRM has been removed, you can do just about anything to the book's text using Calibre or Sigil. You could even just rename it to filetype .zip and use Windows Explorer or other such unzip tools to extract all the components, etc, etc. An epub is really just a zip archive of containing HTML for the text, images, and a few additional control files (metadata, etc).
For minor text extraction, the screen snapshot plus OCR procedure ppatt gave might be somewhat easier (or if you are worried about removing the DRM, which we don't do, of course).
Last edited by RAH; 11-26-2012 at 08:38 AM.