Need to retrieve username and password

Need to access 3 joomla web sites on 1 c panel to change user names and passwords as I have forgotten my admin login info. I do have my C-Panel login. After I can access and review these sites I will post a separate project of redoing and rebuilding to a different CMS (or maybe will stay on Joomla?) But for now simply change these user names and passwords (I believe on PHP.ini)? and of course confirm that they work on the 3 domain names/administrator. The web sites (all on 1 cpanel) are tendailycalendars.com barrytowns.com sueostapowich.com