I bought an Nexus 7 (Asus) so that I would have the option of either using the wireless or a SIM card. I do not want to insert a SIM card. It got set up by someone else who uploaded some materials on it. When I turned it on, the 'No Sim Card' messages appears, and I can't get past that to home screen. How do I bypass putting in a Sim Card to use it?