How to unlock an iPhone without a passcode?

I need to get into an iPhone with a four differ passcode on it. How can I guess what it would be? If it makes a difference, it's a 14 year old boys. Don't worry, I'm not going to do anything mischievous or bad, I'm just wondering how to get into it.

Well its a passcode, you aren't getting into it unless you know it.

Did you try 1234? If so then I'm out of suggestions. But yea the point of the passcode is to protect the info on the phone. If you can't get in then it has done it's job well.

Restore it with itunes.

You can unlock your iPhone using the remote unlocking
method. You can get the remote unlock services from
the site http://www.onlinegsmunlock.com and unlock
easily.