How to Make Custom Ringtones for an SMS iPhone

1. Launch iTunes on your computer. Play the song you want to convert to a ringtone. Note the beginning and ending times of the clip you wish to use.
2. Return to the music list in your library and right-click (or ctrl-click on a Mac with a one-button mouse) on the song you want to use. Then choose the 'Get Info' option.
3. Click on the 'Options' tab and enter the appropriate times in the 'Start Time' and 'Stop Time' fields. Make sure that both boxes are checked and that your clip is no more than 30 seconds long.
4. Right-click on the shortened version of your song. Choose 'Convert Selection to AAC.'
5. Drag the clipped song from the iTunes music folder to the desktop. Then return to iTunes and remove the ringtone from the library.
6. Change the ringtone's extension from .m4a to m4r.
7. Double-click on the ringtone and add it to the iTunes library. It should be placed under the 'Ringtones' heading.
8. Connect your iPhone and sync it with iTunes. Your newly created ringtone will be ready to use.
9. Return to the 'Options' tab on your song in iTunes. Deactivate the 'Start Time' and 'Stop Time' settings to restore your song to its original form.