title_body: How do I delete a book off of my Kindle account?
upvoted_answer: Go to 'Manage Your Content and Devices' on Amazon.
  In the 'Your Content' section on that page, locate the row for the book you wish to delete.
  In that the row, locate and click on the Actions button.
  Select the 'Delete' option.
  
  
  NOTE: Though your Kindle Library will list Audible audiobooks, as well as Kindle ebooks, you cannot use this method to delete Audible audiobooks from your Library. Audible currently does not provide users this option. If you insist, you can contact Audible customer support and they will do it for you, or if the book is eligible for refund, you can initiate a so-called 'book return' (and receive a refund) on the Account Details page of Audible.com, where you will see an 'eligible' link in the 'Return' column of the row corresponding to the audiobook you wish to return to Audible.