Help please: How to go from Ios 4 to 3.12?

Hi All,
I need soome help how do I go from IOS 4.0 on the 3G to 3.12?

Thanks everyone!

Please search before posting. I answered this exact question less than 24 hours ago. Frustrating.

http://www.hackint0sh.org/f159/149706.htm

Closing thread, please respond in other thread if necessary.