This is only confirmed working for the AT&T Lumia 1520 and may work as is for other phones but also might require tweaks to the XML (see below). It is very possible to brick your phone with this. Your mileage may vary! From a high level this works by using FiddlerCore to intercept the traffic going to the Microsoft WPflights server that controls the Insider app and responds with our own custom data. The app"HOWTO: Install Windows 10 for Phones on Non-supported devices (and other hacks)"