Currently have a jailbroken 3GS on firmware 3.0 using redsn0w last year. I haven't done anything in terms of upgrading because I really didn't see a need to lose the jailbreak and have to do everything all over again. I used f0recast and I have the old baseband and it's saying I am good to jailbreak and unlock. Now, I sold the phone on ebay to pay for my iphone 4. I want to have it jailbroken and unlocked on 4.0 for the buyer. According to the modmyi walkthrough ( http://modmyi.com/guides/how-jailbreak-iphone-3gs-4-0-pwnagetool-os-x/#more-3270 ) it says I NEED to be on 3.1.2 and jailbroken. Does this mean I have to jailbreak to 3.1.2 and then do it all over again for 4.0? Is there any way to go straight from 3.0 to 4.0? Sorry if this is a dumb question but I want to make sure I don't screw this up and not be able to send it jailbroken and unlocked to the buyer. Is there a guide going from 3.0 to 4.0?