Open iTunes.
Step 2 Find the song that you want to make into a ringtone.
Step 3 Listen to the song and find the part of it you want to use.
Step 4 Write down the start and stop times of the clip.
Step 5 Right-click the song and select "Get Info."
Step 6 Click the "Options" tab.
Step 7 Type in the start time of your ringtone in the text box next to "Start Time" in the minutes:seconds (i.e. 2:01) format.
Step 8 Type in the end time of your ringtone in the text box next to "Stop Time." Make sure the ringtone is no more than 40 seconds long.
Step 9 Click "OK".
Step 10 Right-click your song again and select "Convert Selection to AAC". Wait for iTunes to convert your song. It will create a duplicate version.
Step 11 Right-click the ringtone and select "Delete".
Step 12 Click on the "Keep Files" button.
Step 13
Find the file. It's usually in your User folder under Music > iTunes > iTunes Music and under the band's name. It will have an extension of "m4a." (if you have widows vista scrol down for tips to change M4a into m4r)
Step 14 Replace the "m4a" extension of your ringtone with "m4r". You can either double-click slowly to re-name your file, or right-click and select "Get Info" on a Mac or "Rename" on a Windows PC.
Step 15 Click "Use .m4r" or the PC equivalent when the system warns you that the change may affect the use of your file.
Step 16 Double-click the ringtone file. ITunes will automatically add it to your ringtones folder in your iTunes Music Library.
Step 17 Connect your iPhone and sync your ringtones
In order to change the file extension in Vista you will have to perform the following steps. This was performed on Vista Home Premium w/ SP2 & iTunes 8.2.0.23.1) Open the folder where ringtone is saved.
2) Click on the help icon (?) in the upper right hand corner of the window.
3) Type "Folder Options" in the search box and press enter.
4) Click on option 1 "Change folder views and behavior".
5) Click on the link "Click to open Folder Options".
6) Click on the view tab.
7) Uncheck the box next to "Hide extensions for known file types" and press ok.
8)You should now see the file extension. Rename the file to end with ".m4r".
9) Double click and itunes does the rest.
