Find "ringtones+sounds"
Slide your finger left across the display to open the main menu.
Press Settings.
Press Settings.
Press ringtones+sounds.
Select your ring tone
Press the field below "Ringtone".
Press the play icon next to the required ring tones to listen to them.
Once you've found a ring tone you like, press the required ring tone.
Return to the home screen
Press the Home key to return to the home screen.