The first thing we’ll need to do is choose a song in iTunes to use as a ringtone. Open up iTunes on your Mac or PC and click on the My Music tab, or choose Music from the dropdown menu at the top left then select Library from the options underneath the main display window (this depends on the version of iTunes you’re using). Choose a song that’s on your hard drive then right click on it, choose Get Info, then click the Options tab.
Within the main panel you’ll see settings for Start and Stop. A ringtone can only be thirty seconds long, so use these settings to isolate the part of the song you want then click OK. You won’t be deleting anything on the actual track itself, so don’t worry.
Now highlight the song, go up to File at the top of the screen and select Convert > Create AAC version (in older versions of iTunes the process was File > Create New Version > Create AAC version). iTunes will duplicate the track, but if you look closely you’ll see that the new version is only 30 seconds (or less) long. That’s the one we’ll use for our ringtone.
Remember to go back to the original track now and untick the Start and Stop options, otherwise the track will only play that short section.