forgotten password for setting in avast

as i have to change the settings of avast, i had kept a password i forgot it. can any one help me out how to find it. it is neither uninstalling from the control panel?

if password is lost you need to reinstall…

remove avast with this tool … read instructions http://www.avast.com/en-eu/uninstall-utility
download and reinstall http://www.avast.com/en-eu/download-software

If you need your license again after a clean install:

For the free version:
www.avast.com/resend-license-free-antivirus.php

For paid versions:
www.avast.com/resend-license-free-antivirus.php