I took at look at the manual at: Rain Bird ESP-Modular User Manual
In the first photo, I see top row VT (nothing connected), MV (nothing connected), and COM (common).
Bottom row (including what was just listed) zones 1-12 followed by AUX.
The third picture shows the first two as 24 VAC, GND, and then two SENS (connected).
To me, this is a straight forward conversion. Connect the Rachio power to an outlet and then to the Rachio. COM wires go to one or more of the C, zones 1-12 to 1-12 on the Rachio, and it appears AUX can be another normal zone or something like lights that are not affected by rain. I would presume you will just hook this up to zone 13 on the Rachio.
So, what would be the process for me:
- Take pictures (done)
- Disconnect power from the old controller
- Possibly label the wires as you disconnect them
- Probably remove the old controller
- Put up the new controller
- Route the wires and connect them to the correct location
- Route Rachio’s power cable and connect to the Rachio
- Plug in the other end of the power into an outlet
- Connect to WiFi and set up the app, etc.