How to install windows 10 in nokia lumia 520

THE WINDOWS 10 INSIDER PREVIEW IS NOW AVAILABLE FOR NOKIA LUMIA 520

first of all you can open WINDOWS Store in your phone,and search 'windows insider'

Then install the insider app.

 Open the insider app.

after open it we can see two insider options .one is insider slow and second one is insider fast . tap on insider fast ,then your phone restart automatically,after restarting your phone .

go to settings>phone update >check updates>download it

install.........