1. Hold down the Power button in order for the menu to show on screen.
2. Choose the Power off option.
3. After a couple of seconds, hold down the Power button again. Your phone will turn back on. Voila.
1. Find the Reset whole button. It should be located at the bottom of the device.
2. Find the Reset button and use something thin (stylus or a needle, or a particulary thin nail) to press it.