HOW TO FORMAT NOKIA LUMIA 520

If you forgot your Screen Password lock,
If you want to erase your personal data,
if you have a problem with applications,
you can perform a Hard / Factory reset.

Warning!!!
Resetting your phone will erase all content stored on your phone,
including apps and games (along with app data and game progress)
Text messages, call history, music, photos and more.

Resetting your Windows Phone
will return it to the state it was in the first time you turned it on.
All of your personal content will be erased,
and the phone will be restored to its factory settings.