Download and install Calibre software.
Download Apprentice Alf’s deDRM plugin from Apprentice Alf’s Blog or from Github.
Open the zip from 2 above and copy the file DeDRM_calibre_plugin\DeDRM_plugin.zip to your desktop.
Open Calibre, install the plugin.


Configure the plugin by entering your Kindle’s serial number in it.
Restart Calibre, and import your exported book.