Launch WPInternals. It should detect your phone in "Normal Mode." Navigate to the section on the left menu.
The Lumia 520 achieved legendary status due to its rock-bottom price tag and surprisingly robust build quality. It shipped with a dual-core 1.0 GHz Snapdragon S4 Play processor, a 4-inch display, and a meager 512MB of RAM. Nokia Lumia 520 Custom Rom
Nokia Lumia 520 is one of the most popular Windows Phone devices ever released. While it originally ran Windows Phone 8, its massive user base led to an active development scene aimed at extending its life through custom ROMs and experimental operating system ports. Core Tools for Customization To install any custom ROM on a , the primary tool required is Windows Phone Internals (WPI) Launch WPInternals