Instruction I:
1. Hi. Start by pressing and holding the Power button. Release it when a menu appears on screen.
2. Next, select the Power off option.
3. Press & hold the Power button until the phone turns back on. Well done!
Instruction II:
1. First of all, take off the phone's back cover and remove the battery.
2. Wait a few seconds and reassemble the phone. Lastly, press the Power button to turn it on. Done!