How do I rewire a doorbell?

Here's a post that might help - https://www.familyhandyman.com/electrical/electrical-repair/repair-a-doorbell-fix-a-dead-or-broken-doorbell/

Doesn’t the Nest doorbell use WiFi and a battery?

Which Nest do you have? The video model needs to be hardwired to the existing doorbell wiring or you need to run new wire. You may also need to place an adapter inside your existing interior chime box. If your current doorbell does not work, you need to go through some steps to determine exactly where the problem is. See if this helps:

https://www.familyhandyman.com/electrical/electrical-repair/repair-a-doorbell-fix-a-dead-or-broken-doorbell/

We just bought a battery door bell that sticks on. No wiring. We lived in a big 2 story, and it worked great.