1. Visit the router's IP address in a new browser window.
http://192.168.1.1 is the default but if that doesn't work your router manual should provide the correct URL.
2. Enter the Admin username and password for your router. On this model these credentials should be on the bottom of the router on a sticker.
3. Click on the My Network icon:
4. Click Network Connections from the left hand menu then choose Broadband Connection (Ethernet/Coax) (or Wan PPPoE if using DSL, you will see that WAN PPPoE is Connected in that case):
5. Click Connection Properties from the left hand menu then Settings at the bottom of the page:
6. Scroll Down to where it says DNS Server and change the drop down menu so it says Use the Following DNS Server Addresses. After changing the drop down you will see the options for Primary and Secondary DNS Servers. Add 208.67.222.222 for Primary DNS Server and 208.67.220.220 for Secondary DNS Server and hit Apply at the bottom of the menu: