Tap the menu icon.

Tap Gallery.

Go to the required folder.
Tap and hold the required file.

Tap Share.

Tap More.

Tap Bluetooth.

If Bluetooth is turned off:
Tap OK to turn on Bluetooth.

Your mobile phone now searches for devices and after a moment, a list of Bluetooth devices within range is displayed.
Tap the required Bluetooth device.
The file is sent.

Tap the Home key the necessary number of times to return to the home screen.