1. From the home screen, swipe down from the Notification bar with two fingers.
   
2. Tap the Settings icon.
   
3. Scroll to then tap Sound & notification.
   
4. To change the notification alert sound, scroll to then tap Default notification ringtone.
   
5. To edit messaging alerts, tap App notifications.
   
6. Scroll to then tap Messaging.
   
7. Tap to toggle the desired settings on/off.