Samsung Galaxy S6 edge +

Slide your finger down the display starting from the top edge of your phone.

Press the settings icon.

Press Sounds and notifications.

Press Ringtones and sounds.

Press Ringtone.

To use one of your phone's default ring tones:

Press the different ring tones to listen to them.

Once you've found a ring tone you like, press the Return key.

To use one of your own ring tones:

Press Add ringtone.

Press the different ring tones to listen to them.

Once you've found a ring tone you like, press DONE.

Press the Home key to return to the home screen.