here is a link to the latest way to do it on your phone if you have garage band. I just did it to see if it works and was able to make a ringtone from a song I already had in about 5 minutes, I just read this and was able to do it.
Steps for creating Ringtones :
1. Open the Garageband app.
2.Tap the [+] BUTTON placed at the top left corner, then select any LIVE LOOP.
3. Click on the CIRCULAR LOOP icon placed on the top right corner.
4. Select MUSIC tab.
5. Click on the SOUNDS.
6. Then select your favorite song from you library.
7. Hold and drag that song on any of the BLUE BOXES on the screen.
8. Press DONE on the top right corner.
9. Let the song load. Once it is loaded, PLAY it.
10. Then tap on the the RECORD BUTTON placed at the top of the screen to record your favorite part of the song.
11. Once the recording is done, click on the STOP BUTTON placed besides recording button.
12. Then select INVERTED TRIANGLE placed at the top left corner, Select MY SONGS.
13. Then click on the "SELECT" at top right corner. Select your new song that you have just created. 14. Click on the SHARE BUTTON placed at the top let corner. Select Ringtone. Give it a name.
15. Click on EXPORT placed at the top right corner. Your ringtone is ready. Select OK.
16. Go to SETTINGS - SOUNDS - RINGTONES . Select your new Ringtone that you have just created.