How to install iOS 7 on iOS 8 in Ipad mini?

Hi Everyone,
I want to know that is it possible to install iOS 7 on my IPad which iOS version is iOS 8 now. Please tell me is it possible to do or not and if it is possible to degrade my IPad OS version to iOS 7 then what is its procedure, Please guide me step by step so that I can understand easily. Thanks in advance.
