How to take iOS 7 off my iPhone?

I downloaded iOS 7 on my iPhone without knowing that i needed to be part of a developer program for it to work. Now my phone won't activate and i can't get to anything on it. I need to know how to take iOS 7 off and go back to iOS 6. Please Help

You can't downgrade your iOS without resetting to factory settings.

Read here
new-articles4u.blogspot.com/2013/06/io…

I need to know how to because mine done the same thing