How can one delete the system update on an iPhone 4 to its previous update?

I recently updated my iPhone 4 to the new iOS 7.1.1 but I want to delete that system update and go back to the old one, so is it possible, and can someone show me how to do it?

It is possible. But you have to be a extremely skilled coder/hacker to do so. There's not just like a program online like you would use to jailbreak. So unless your a good hacker or have a friend who is you can't do it.