How to Downgrade an iPad 2 from iOS 6.1 Beta 2 to iOS 5.1.1 without shsh blobs?

I need to know as soon as possible… i put my ipad 2 in dfu mode already so what should i do next? i keep getting error 1600 from itunes..thx
>>> How to Downgrade an iPad 2 from iOS 6.1 Beta 2 to iOS 5.1.1 without shsh blobs?