You can select the ringtone you want to hear when you get a call.
Find "‹SIM› ringtone"
Tap ‹SIM› ringtone.
Tap Music on device.
Tap the different ringtones to hear them.
Once you've found a ringtone you like, tap arrow left.
Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.