1. Open iTunes and select a song, right click selected song and select "get info"
2. Select the Options Tab in the window that pops up
3. Enter the start and stop times of the song you have selected for the part of the song you want as your ringtone**MAKE SURE THE TIME FRAME YOU DECIDE TO USE IS 30 SECONDS OR LESS** (listening to it first and writing down the exact times is much easier then guessing by the way) then click OK
4. The "get info" window will go away and then play your selected song, it should start at the time you told it to start, and stop at the time you told it to stop. you can allways go back and edit your inserted time frame.
5. Once you have the 30 second or less portion of the song playing when you want it to and stopping when you want it to, right click on the song and select "create ACC version"
6. A new copy of the song will appear in your library. Make sure the song lenght says 30 seconds or less.
7. right click the song and click show in finder or show in explorer
8.a window opens with the location of the file. you need to edit the file extension (example - your ringtone.m4a) to (your ringtone.m4r) the .m4r extension is the ringtone format for iPhone. **NOTE** you can goto tools>folder options then click the "view" tab and make sure the option to "Hide extensions for known file types is NOT selected, that way you can see what file is what type. You do not need to do this to make the necessary changes tho, just typing in ( your ringtone.m4r ) changes the file extension automatically.
9.drag the .m4r file your just created to your desktop.
10. in iTunes deleted the AAC version you created (the 30 second or less clip that you made as your ringtone, so your original WHOLE song is there, and go back to get info and change the start and stop times back to what it should be..start-0.00 and stop - however long the song is. the .m4r file on your desktop will not be deleted when you delete the AAC version that is in your iTunes.
11. Double click the file on you desktop to add it to the ringtones section of iTunes (this happens automatically when itunes tries to play the file.)
12. Connect and sync you iphone, after sync is complete goto the setting app on your iPhone and goto sounds, and select the ringtone section to view your new ringtone. it will appear under a custom category.
**if the ringtone does not appear in your list of ringtones, you may have to restart your iphone, hold downt he power for 5 seconds and then slide to power off, check the list again once your phone is restarted.**