How to activate the Verizon iphone 5 without service?

I've already heard that the verizon iphone 5 is factory unlocked, BUT how can you bypass the activation screen in the setup without service? What kind of sim card do you need and can i just use a tmobile or at&t nano sim card to bypass the activation screen? Connecting it to itunes will no activate it unless i have a sim card.

Any sim nano sim will work, or a shaved down micro