You have to download a 3.0 .ipsw
Originally Posted by MAAD
A simple google search for iPhone 3.0 ipsw 3GS should bring it up. Just make sure you download the file for the 3GS, not the 3G or 1st gen iPhone.
The filename has 2,1 in it, if it has that, it's right.
You will use redsn0w version 0.8 and when you launch it, it will ask you to navigate to your version of firmware, that's where you located the 3.0 ipsw you had to download.
After that, you're done.
(If you can't find the 3.0 ipsw for some reason, let me know in this thread and I'll upload it to my mobileme public disk and PM you a link.
That goes for anyone else as well. If you need an ipsw or anything, just post, either me or another member can either send a link or upload the file.