How to override iphone passcode?

My wife and I would like to unlock our deceased daughters iphone 4S. We knew it but have forgotten.

You must restore it. If there's something you don't want to lose on it call apple and explain the situation.

Obviously it wouldn't be a security code if you could just bypass it. You can wipe it back to factory but if it has iOS 7 you won't be able to do that without the icloud password.

Without the passcode, you're out of luck. You can reset the device, but then you have to know the password for the Apple ID.