Unpairing and Pairing Venstar T200O Thermostat with ACC-TSENWIFIPRO Sensor

Unpairing and Pairing Venstar T200O Thermostat with ACC-TSENWIFIPRO Sensor

I have an ACC-TSENWIFIPRO sensor which was connected for a little while. We had some issues with WiFi and it disconnected. After we fixed the WiFi, it wouldn't connect. My thermostat is a Venstar T2000. Is there another way to unpair and pair this sensor since the T2000 has no accessory button?

Or how better can I go about it?