1 ) Close any web browsers with Evernote plugins:
* Close Safari
* Close Firefox
2 ) Ensure that the Evernote Helper is not running
(It is not sufficient to reboot the system if the Evernote helper is set to restart on login )
In a terminal session
ps alwwx | grep -i evernote
Kill the process "EvernoteHelper"
3 ) Remove the following files
(This may require root privileges - as 'sudo')
sudo rm -rf /Applications/
Evernote.apprm -rf ~/Library/Application Support/Evernote
rm -rf ~/Library/Preferences/com.evernote.Evernote.plist
rm -rf ~/Library/Preferences/com.evernote.EvernoteThumbnailer.plist
rm -rf ~/Library/Preferences/com.evernote.SafariClipperPlugin.plist
4 ) Download and reinstall Evernote using the standard process
https://discussion.evernote.com/topic/77444-how-to-completely-remove-and-reinstall-en-mac/