How to Downgrade windows 8 to windows 7 on Inspiron 15R (5520, Mid 2012)

[DeepakKochar]

I want to degrade my window 8 to windows 7 of my dell laptop Inspiron 15R (5520, Mid 2012) so please guide me

 

[Java1000]

A much as i know, the only legal way to do this is to get the original windows 7 cd, but the illegal way is ... <mod edit>