A Confirmation dialog appears that says the plugin has been installed. Then click on the 'Yes' button in the warning dialog that appears. Use the file dialog button to select the plugin's zip file (K4MobiDeDRM_vXX_plugin.zip) and click the 'Add' (or it may say 'Open' button. Click on the 'Load plugin from file' button at the bottom of the screen. Under 'Advanced' click on the on the Plugins button.

Do **NOT** select 'Get Plugins to enhance calibre' as this is reserved for official calibre plugins', instead select 'Change calibre behavior'. It is meant to function without having to install any dependencies except for Calibre being on your same machine and in the same account as your 'Kindle for PC' or 'Kindle for Mac' application if you are going to remove the DRM from those types of books. Calibre can then convert them to whatever format you desire. This plugin is meant to remove the DRM from.

If you install this plugin, those plugins can be safely removed. This plugin supersedes MobiDeDRM, K4DeDRM, and K4PCDeDRM and K4X plugins. Plugin for K4PC, K4Mac, standalone Kindles, Mobi Books, and for Devices with Fixed PIDs.

Calibre remove drm from prc