From a Home screen, swipe up from the center of the display to access the apps screen.
Tap Messages .
shareIf prompted to change the default SMS app, tap NEXT > YES to confirm.
From the Inbox, tap the message containing the ringtone.
Tap and hold the attachment box.
Tap Save attachment.
By default, the sound file is saved to: My Files/Downloads.
To view the sound file as a ringtone option, it must be moved to: Internal storage/Ringtones.
You can use the File Manager app (swipe up from a Home screen then tap File Manager) to move files.