Since its introduction, Windows Phone users have been hoping to change the mobile operating system in the default application, but unfortunately Microsoft has never let it achieve until the Windows Phone 8.1 to see a different point. In Windows 10 Mobile, the current addition to SMS applications and some call options, Microsoft did not open more. But today, a user named LinkSatonaka on the Reddit site drying out the first can change the Microsoft Edge browser settings, the system version number for the Windows 10 Mobile build 14946.
Although it has not been officially confirmed, but it at least let us see a ray of dawn. Unfortunately, when you press the Change My Defaults button, it will take you to the main page where you set up your app.
This could mean two things:
 It is a mistake from the PC platform transplanted bug (such as Windows Spotlight);
 This is an early leak feature, the developer forgot to remove it from build 14946.
We very much hope that the latter case.