Installing the Nest Thermostat is fairly simple. 
The first step is, of course, turning off the main breaker for the HVAC system.
The included tape flags can be used to identify the wires. Once the wires are labeled, the old base can be removed.
Since there were some blemishes on the wall left by the old thermostat, I decided to mount the Nest base on one of the mounting plates. The Nest
includes drywall mounting hardware. The Nest base clicks into the mounting plate. The spirit level on the base can help to mount the Nest. Two screws keep the base and the mounting plate securely fastened to the wall.
Once the base is fixed to the wall, the last step is to connect the wires by pushing down on the connectors and slipping the wires into the holes. Once all of the wires are connected securely, the Nest is ready to be plugged in.
Here’s a short video I threw together showing the basic setup of the Nest Thermostat:
















