To power off Rest+, press and hold the volume down and brightness down buttons on the base of the device for 10 seconds. In powered off mode, the Wi-Fi and touch ring will be disabled which will help preserve the battery life and facilitate on-the-go travel.
To power Rest+ back on, either plug it in or press and hold the volume down and brightness down buttons for 10 seconds. After it is plugged in, your Rest+ will try to reconnect to Wi-Fi. However, you may need to go through Settings to update your Wi-Fi connection.