How can I downgrade from 4.1 to 3.1.3

[stiverphoto]

So, I picked up a used iphone 3g and it has 4.1 installed on it. I am hoping someone can tell me what the best tools are to downgrade to 3.1.3 and a bit of instruction as well. I have used redsn0w in the past and want to make sure this will work since I don't have SHSH saved since it is a used iphone. I don't really need the unlock so I'm not worried about the baseband. Any help you guys can give me would be greatly appreciated Thanks ahead of time.

[iYeow]

Download 3.1.3 fw and put your iphone into dfu mode
Run itunes and shift + restore to 3.1.3 ipsw
Exit recovery from the feature of Tiny umbrella.
Now you are at 3.1.3 fw .

[stiverphoto]

Oh wow....it's that easy? I had no idea. Thank you so much bud!!

[iYeow]

Yes, no shsh blob for to 3.xx, easy as A,B,C.