Installing a custom ROM on the is a classic "legacy tech" project that can breathe new life into one of the most popular Windows Phones ever made. While official support for Windows Phone 8 has long ended, the enthusiast community (particularly on XDA Forums ) still maintains resources for experimenting with alternate operating systems. Custom ROM Options for Lumia 520
To install any non-official software, you must first bypass Nokia's original boot security. Connect your Lumia 520 to your PC via USB. Launch the software on your computer. Nokia Lumia 520 Custom Rom
The Lumia 520 is highly regarded in the mainline Linux community as a cheap development board for mobile Linux distributions. Essential Prerequisites and Tools Installing a custom ROM on the is a