Connect your phone to your computer via USB and open the Phone storage folder.
Don’t have access to a computer or a USB chord? Install a file manager app like Astro.
Locate the directories: Ringtones, Notifications, Alarms in the storage folder (create them if not found)
Any music files placed in these directories will appear in their respective menus in Settings. That’s it!
You can also use Ringdroid to cut a song and use it as a ringtone.