How to restore my iphone without getting the update iOS 7?

So, I downloaded iOS 7 but haven't installed it because there's no more room for it on my 8GB iphone4. I want to get rid of iOS 7 and since I haven't installed it yet people tell me I can just restore my iphone but the only option I have on itunes is to restore AND update my iphone with the new iOS 7 update which is not what I want. Is there another way to restore my phone without installing iOS 7 so I can finally be rid of it?

You will have to refresh the software of your iPhone. The space 8gb is insufficient.