Move the ON/OFF button from its OFF position to its ON position, which is the middle of the cutout. It will remain there, and the headphones are now ON. The blue LED will start blinking, indicating that Bluetooth pairing is possible. If you need to reset the BT pairing, move the ON/OFF button against the spring load, to the opposite position of the OFF position, and keep it there for about 5 seconds. Now the BT system is reset, and new pairing is possible.