How to unpair bluetooth device from the command line

first of all start your Bluetooth from System settings.

Open terminal and type:

bluetoothctl

then you will see the list of devices you have paired with and their corresponding MAC address. To un-pair a device type:

remove aa:bb:cc:dd:ee:ff

replace aa:bb:cc:dd:ee:ff with the MAC address of the device to un-pair.

there is no un-pair commmand