I think how to change the ringtone of Apple's mobile phone is the default.

Here, taking the iPhone 7 mobile phone to modify the SMS ringtone as an example, the specific method is as follows:

First click the "Settings" icon on the mobile phone desktop, as shown in the figure.

2. Then select the "Sound" option in the setting interface of the mobile phone, as shown in the figure.

Third, then open the "SMS ringtone" in the sound interface to enter, as shown in the figure.

4. After entering, you can choose the type of SMS ringtone you want to set. Take "Classic" as an example, click to enter.

5. After entering, select the SMS ringtone to set.