How can I downgrade an iphone from 1.1.3 to 1.1.2?

I couldn't find it anywhere. Any guide or instructions?

Thanks!

you can't downgrade to 112.
you have to go down to 111 first then you get to upgarde to 112


dock your iphone,. launch itunes and choose restore, pick firmware 1.1.1
or read this.
http://iphone.unlock.no/#how-to-down...1.1.2-or-1.1.3

Thanks! But it says that it's not possible on phones that already had 1.1.2 or 1.1.3

"At the moment this is NOT possible if your phone already had 1.1.2 or 1.1.3 when you bought it (meaning it has the new bootloader)."