[Windows Central Question]

i want update my lumia 520 with windows 8.1 software in place of windows 8

[xandros9]

You can use Settings > phone update, which is the primary way people update their phones.

There are other ways, but involve erasing the phone, which might not be a bad idea.

[pankaj981]

Or... The other way would involve downloading the Windows Phone Recovery Tool on a PC and updating your phone using that. This method, as mentioned above would factory reset your phone during the update