06-24-2013 04:33 PM - edited 06-24-2013 04:34 PM
Go to mynook.barnesandnoble.com and log in. Select the "Library" link to open your library. Locate the book you'd like to delete and select to delete it.
Be advised that this will remove the book from EVERYTHING and if you want to read it again, YOU WILL NEED TO REBUY IT TO READ IT. There is no going back.
OR... Read the two very well written answers above that were ALREADY THERE when you asked this question.