KFMon has an uninstaller:
https://www.mobileread.com/forums/sh...d.php?t=274231
Get the latest release of the KFMon uninstaller ( KFMon-Uninstaller. zip ).
Ensure your Kobo is powered on, then connect it to your computer.
Copy KoboRoot.tgz to the .kobo directory on your Kobo.
Safely eject your Kobo, then unplug it.
Allow your Kobo to reboot.
Then delete any residual kfmon files and folders from .adds directory