I just had the same issue. First you need to create a new home with the new Nest Router. You can use the same name and password so all devises will still log on like before. You will need to use the QR code or the code on the bottom of the Nest ( it is really hard to see as it is just engraved in the back and not colored).
Next you have to deal with the older Google points. I unplugged each of my old points and reset them individually one at a time. You press the reset button and after about 5 min it will show a solid blue light. You can reset all of them before setting anything up as it takes a few minutes for them to reset. They will be identified by the serial number on the bottom of the point in the WiFi app. Select one in the app and add it to your system.
Google really needs to post better instructions. Hope this helps. FYI do not use the flat modem wire that comes with the Nest. It cannot handle high speeds. Get a round quality wire and you should have better speed. Lastly, test the mesh in the app. The new app doesn’t show the point speeds, which sucks, but it works fine. There is always some degradation at each connection. I have 1.11 G coming in and only 700 leaving the router. My old points showed about 250 mb so there was loss. Good luck.
