Subscription to the entire suite I assume is expiring? Just uninstall everything McAfee from Control Panel, then run the MCPR cleanup tool listed under Useful Links at the top of this page and reboot.
There hasn't been a standalone Parental Controls for ages now so if you have it perhaps you should be contacting Technical Support also via Useful Links.
If you just want to disable it, sign in as the Admin and simply turn off filtering for each account.
This isn't a Dell version of McAfee is it? It should uninstall and cleanup up using the MCPR tool similarly.