Converting .snb files directly to .txt format.
To our knowledge, two different types of possible .snb to .txt conversions exist.
Your best option to do that is to download the S Note tool from Samsung's website. Then simply import your .snb file using the 'File -> Import -> S Note files' function. Export it to .pdf format, and either convert .pdf to .txt using several converters, or simply copy and paste the document's content.
To convert snb to txt, use software, such as the popular Calibre ebook management tool, with which you can easily export contents from Shanda Bambook eBooks.
A free e-book library management application
A mobile note making app for Galaxy Note
A desktop app for handling S Note documents