My iPhone's screen is broken/non-responsive. How can I reset it without my passcode?

My brother broke his iPhone and the touch screen is severely cracked and it wont work, at all. Verizon just sent my brother his replacement. I plugged it into the computer to use through iTunes, but I need to unlock his phone. The screen is blank and non-reponsive. Is there any way that I can reset it through iTunes without his passcode? Thanks ^^