Lumia 520 started receiving Windows Phone 8.1 and Cyan updates
According to Nokia’s support page, the first Nokia Lumia 520 devices have started receiving the Lumia Cyan software update. Orange France is now rolling out the software to all Lumia 520 owners in the country. Carriers around the globe are still testing the Lumia Cyan update though we expect to be unleashed for all users in the next few days.
Lumia 520, the most popular Windows Phone device with over 12 million activations, is the third smartphone after Lumia 635 and 925 to receive the Cyan update.
See if an update is available for your device here, or just head to Settings -> Phone updates.
Microsoft recommends making enough space (at least 1.5 GB) on the phone and charging the battery before starting the procedure.