It's a waste of time trying to get any real help from 1st level tech support by telephone. Ask for a supervisor or have them schedule an in home technician visit if you're not real tech savvy. You're already paying the tab for equipment rental / support, so may as well avail yourself of it. Anyhow, It's pretty simple to set up different DNS servers to replace the Frontier DNS.
Go To: »192.168.254.254/htmlV/welcomeMain.htm
to view the Browser based, settings GUI. Easy, 3 click process.
Click where you see the Red Arrow's to change DNS. Remember to right down previous settings before changing anything so you avoid having to resort to a "default settings modem reset."