How to reset iPhone 3 without a computer?

Recently I got an old iPhone 3 and I was gonna use it as my phone and use my current iPhone 4 as an iPod (the iPhone 3 has more room). I put a password on it and I can't remember what it was. It doesn't have iOS 7. Is there a way I can reset it without a computer?

Well I would assume you go into too your settings and find the one that say device and scroll down too the end and usually there's some kind of rest button there