How to make an itunes song into a ringtone?

I've tried everything, when i go onto itunes and right click the song i want and click get info it won't let me shorten the song, i have the newest version of itunes and an iphone 3gs with iOS 6 i don't want to go onto any paid website or ones where you have to put your mobile number in, thanks

Download a ringtone app, choose the song you want to do, and normally the way they work is that through the app you create a 30 sec or so ringtone, then connect it to itunes, go to apps, and then transfer them to your computer, and then back to the ringtones section of itunes.

You can also make iphone ringtones by yourselef with a rigtone tool like this:

http://www.softivy.com/iphone-ringtone-maker-avc.php

Well that effectively limits to this longer, but I find personally better method
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