Jailbreak iPhone 4 Jailbreak iPhone 4

How do I safely update my jailbroken and unlocked iPhone 3g 3.1.3 to os 4.0?

I have iphone 3g 3.1.3 jailbroken and unlocked with ultrasnow 0.93. I want to update iphone to new os 4.0. I know I can jailbreak and unlock 4.0 with redsnow and ultrasnow, but how do I update it to begin with? Do I need to use a 4.0 ipsw file and hit shift then update on itunes, or do I just click on update on itunes and use official 4.0 update?

yes you need to update the ipsw file and you can use redsn0w 0.9.5 and re-jailbreak it but it will be perfectly safe

* if you have a Jailbroken iPhone 3G at 3.1.2 (but not jailbroken with Spirit) then you should create the ipsw with PwnageTool 4.01 and restore from recovery mode or DFU mode.
* if you have an out of the box iPhone 3G you should restore using a PwnageTool 4.01 ipsw using DFU mode.
* if you have a Jailbroken 3.1.3 iPhone 3G it is very possible that this can fail from recovery mode, if this failure happens you will need to restore using DFU mode.
* As an alternative to PwnageTool, you can use redsn0w on iPhone 3G (on both Windows and Mac) as mentioned in our last post.

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