1, From the iPhone's home screen, tap the Settings app.
2, In Settings, tap Sounds in the third group of options.
3, In Sounds, swipe down to the Sounds and Vibration Patterns section. In that section, look for Ringtone. That displays what you have set as your current iPhone ringtone. Tap it to change that.
4, This menu shows you the list of all the ringtones available on your iPhone.
To get new ringtones, tap the Store button in the top right corner. This will take you to the ringtone section of the iTunes Store where you can stock up on new ringtones.
5, If you choose not to buy new ringtones, but instead use the ones loaded on your phone, the first set of options in the Ringtones section are ones that you bought from the iTunes Store or created using another app and have synced to your iPhone. The ones below the divider came pre-installed on the iPhone.
Alert Tones, farther down the screen, aren't ringtones exactly. They're alert sounds normally used for alarms and other notifications, but they can be used as ringtones, too.
6, When you tap on a ringtone, it will play so you can preview it and decide if it's what you want. When you've chosen the ringtone you want to use as your default, make sure it has the checkmark next to it. Then tap the Sounds button in the top left corner or click the Home button to go back to the home screen. Your choice is saved automatically.