Techy stuff: How to install Windows 8.1 Preview for developers(windows 8.1 for nokia lumia 520,525),windows 8.1 update for nokia lumia 520

Sign up for Microsoft’s App Studio: appstudio.windowsphone.com which is free of cost, using your Microsoft ID which is used on your phone and allow them to register your email address. Once you have the confirmation on the account created, now you need to install an app on your phone.
Install the Preview for Developers app and then sign in with the same ID which you used to create the App studio account in step 1.
Now you can see an option “Enable Preview for Developers”, check the option and click done.
That’s it. You are now enrolled to the developers program. Now when the update is released, Go to Settings-> Phone Updates and click check for updates button and you will be able to see the updates.
Note:
Windows Phone 8.1 preview will work on all Windows Phone 8 devices including Lumia 520, 525, HTC 8X, Samsung ATIV etc. It will not work on first generation phones like Lumia 800 and Lumia 900.
Once you have installed it update, you cannot roll it back to previous update.
It will not damage your phone or cause any issues.
The update will not factory reset your phone or wipe off the data in the phone.
When the final Windows Phone 8.1 update is rolled out, you can still install the update the same way
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