unable to uninstall Lenovo password manager FF extension

If you have already removed the client security stuff on your IBM Lenovo Thinkpad, but are still unable to uninstall the thinkvantage password manager extension / add-on from Firefox because the button is disabled or greyed out here's how to manually remove it:

Delete the registry entry for it in:
HKEY_CURRENT_USER\Software\Mozilla\Firefox\Extensions "{FCF36B88-1BBA-487f-B64B-D2E8980A9293}"="C:\Program Files\Lenovo\Client Security Solution\PWM Firefox Extension"