The Nano 2 ships already paired, but in the event you need to re-pair the units, you can go into the menu of the Hand Wheel and select Connect, then 2.4G and select Channels.
You can use the icon in the top left corner to switch between Manual and Automatic pairing. Manually pairing is used for connecting the motor to one specific channel while Automatic pairing will find the cleanest channel out of the selected options.
You can then press Search on the menu and double click the Pairing Button on the motor. Once the motor appears on the Hand Wheel display, you can press Confirm to sync them together.
The motor is now set to the channel that is displayed on the top left of the home screen on the Hand Wheel.