Indeed there is a way to downgrade your Windows Phone from 8.1 to Windows Phone 8.0

Enough people chose the red pill that it crashed Microsoft’s App Studio for a few hours when the developer preview for Windows Phone 8.1 dropped last Monday.
For the geeks in the room, they are more than likely willing to put up with these issues while they continue tinkering with Windows Phone 8.1 and learn more about what to expect when it finally has its commercial rollout later this summer. For others some of the changes they are seeing are bringing feelings of buyer’s remorse, and perhaps they wish they took the blue pill instead. Alas, they should have known it would be a one-way trip.
Alin Gheaja uploaded a video in which he claims he has been able to reflash his Lumia 720 several times successfully from Windows Phone 8.1 to Windows Phone 8.0. Perhaps not ironically, it is Nokia’s own desktop software that does the heavy lifting.
The process itself is pretty simple:
- Back up your data, because you will lose it
- Download and install Nokia Software Updater (see below the source link)
- Connect your Windows Phone with the screen unlocked and Nokia Software Updater running
- The app will say there is an update available
- Follow the prompts to install the “new” firmware
Surprisingly, that is it. Alin’s video is below. Everything is pretty basic, so you should fare okay if you choose to give it a shot. Just remember the caveats and we offer no guarantees. It is safe to assume that this procedure would not work with a Samsung, Huawei or HTC Windows Phone, but chances are if you have a Windows Phone it is a Nokia anyway. Let us know if decide to take your Windows Phone back to 8.0 and why. Also let us know if you were successful in the endeavor.
sources: Alin Gheaja (YouTube) via WMPoweruser
Download Nokia Software Updater (will prompt to download installer)