Check to confirm that the Bluetooth icon is not on the watch display. If it is, enter the Timekeeping Mode and then hold down the D button for about two seconds until the Bluetooth icon disappears.
When the control indicator is displayed, the watch is in the Control Mode. In this case, hold down the B button for about three seconds to exit the Control Mode and then disable Bluetooth (Bluetooth icon disappears).
On the phone you want to unpair from the watch, perform the steps below.
On the top menu of the CASIO WATCH+ app, tap the following items in sequence: "General" - "Delete pairing".
On the screen that appears, tap "Delete pairing".
This will clear watch pairing information stored by the CASIO WATCH+ app.
Tap the Home button to return to the Home Screen and then tap "Settings".
If it is disabled, tap "Bluetooth", and then tap "OFF" to enable Bluetooth.
To exit the CASIO WATCH+ app
On the phone (iPhone) Home Screen, quickly tap the Home button twice.
A list of the most recently run applications will appear.
Sliding the CASIO WATCH+ app screen upwards will exit the CASIO WATCH+ app.