How to unlock Kindle Fire HD from Demo mode?

Before you ask, no I did not purchase a stolen kindle, nor did I steal it myself. My dad works at Gamestop and he is a manager. Usually managers get first dibs when the company gets ready to throw things away. So my dad took home the kindle fire hd but it is stuck in demo mode. I can't click "more" when I pull down the bar and I can't go into settings because it says, "This feature is not available on the demonstration model. I've looked around on the internet but it says it needs some cord and others say it can be done at all. Is there anyway ro do it without having to purchase anything else? If so, please leave links and detailed instructions. Thanks! :)

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