Soft resets are usually conducted in an attempt to fix malfunctioning applications or because they're required for software installation.
Soft reset contrasts with hard reset, which removes all user data, settings and applications and returns a device to the same state it was in when it shipped from the factory.
1. Soft reset is really, anyone can do it just press and hold you power button.
2. There should pop up menu with few options.
3. Click on Reset or Reboot, and wait untill your phone will restart itself.
4. And done! See? that was very easy.