The following instructions assumes you already have your internet set up and working with CenturyLink. It is known to work on these modems:
- ZyXEL C3000Z
- Greenwave C4000LG (fiber modem)
To start, connect the dsl port on the Modem/router CenturyLink device (will call it "modem") to the wall phone jack and then plug in the power cable. Also connect the Google WiFi to power. Do not connect the two devices via ethernet yet.
Once they are both powered on, factory reset both devices. I've found this will cut down the number of problems during setup.