1. Right click on your chosen mp3 song in itunes.
2. Choose Get info
3. In Options tab, put check mark beside start time and stop time. Make sure stop time is 0:30 then click on ok.
4. Right click again on the song and choose create AAC.
5. Drag the 30 seconds song on your desktop
6. Edit the song that you dragged to .m4r
7. Double click to play the newly edited song
8. You should see the edited song in itunes in tones folder.
9. move the song to your iphone in itunes.
