Instruction I:

1. Turn on the phone.

2 Hold down the Power and Volume Up buttons for ten seconds.

3. Your phone will now restart. Voila.

Instruction II:

 

1. First, press'n'hold the Power button until a menu will appear.

2. Second, select the Restart option. You may need to do it twice.
3. You have completed the soft reset. Yeah, it is that easy.