How do I downgrade my iPhone 4 from iOS 5 to iOS 4.3.3?

I recently upgraded to the iOS 5 beta after having a friend verify my UDID with his developer account. I love iOS 5 however it is extremely buggy and can be very laggy at times. With that being said, I would like to downgrade back to iOS 4.3.3. I've searched on Google and so far the only methods out there require your device to be placed into DFU mode and use programs such as Redsn0w and TinyUmbrella to kick it out of the boot. These effectively jailbreak your phone, which I am not interested in doing at this time. Anyone know a simpler way?