The following guide is for the Inteno DG150 and may be similar to other models.
1. Open the web configuration page for the router, typically http://220.127.116.11, http://192.168.1.1, or http://10.0.0.1.
2. Choose Advanced Setup, then LAN from the router's configuration screen:
3. On the Advanced Setup -> LAN page, edit the Primary DNS server to 18.104.22.168 and the Secondary DNS server to 22.214.171.124, then hit Apply/Save.