How do I sideload my Mobi e-book file onto my Kindle Fire?

Sideloading Kindle Fire with access to a computer (easiest):

1. Using a mini USB to USB cord, connect the Kindle Fire to a computer.
2. Download the e-book file on your computer.
3. Using a file explorer program, open up the Kindle (will show as a temporary drive). Also open the folder on the computer with the file.
4. Drag the e-book file from the computer to the Kindle Fire Books directory.
5. Follow your computer’s procedure for disconnecting peripheral devices. The book will now be available in the Kindle Fire’s “Books” tab.

Sideloading using only the Kindle Fire:

1. Download the e-book file to the Kindle Fire using either the browser or via email.
2. Download and install a file explorer program, such as ES File Explorer from Amazon APP market (it’s free).
3. Using the file explorer find the book file (it will be in the main Kindle directory) and copy it (press and hold the icon until the sub-menu pops up).
4. Go to the “Books” folder.
5. Paste the file (with ES Explorer you will need to select “Operations,” then hit paste).
6. Power Kindle Fire off and back on.
7. Your book should be in the Kindle Fire's "Books" tab.