So, your very talented IT person just setup a fancy new ClearOS server/firewall on your network? Is it bocking a legit site that you need to access? Get the ClearOS server's address and your login from that computer expert of yours and follow these steps.
Open your browser and go to the ClearOS IP address or hostname using https and port 81
Ignore the certificate warning
Login
Go to Gateway and Content Filter
Click the edit button by "Site Lists"
Add site under "Exception Site List"