1) Login to Amazon KDP (opens in a new window)

2) Make sure you are on your KDP Bookshelf page.

3) Find the book and next to your book, click the "..." button.

4) Choose "Edit content"

5) Scroll down to "Kindle eBook Preview" and choose "Preview on Your Kindle Device"

6) Then click "MOBI" under Step 1 which will download the file for you.

This is your .mobi file for your book!

Upload it on this signup form and you are all set!