Slide your finger down the display starting from the top edge of your mobile phone.
Tap the settings icon.

Tap Sound.

Tap Ringtones.

To use one your mobile phone's default ringtones:
Tap the different ringtones to listen to them.

Once you've found a ringtone you like, tap Done.

To use one of your own ringtones:
Tap Add.

Go to the required folder.
Tap the different ringtones to listen to them.

Once you've found a ringtone you like, tap Done.

Tap the Home key to return to the home screen.