How to upgrade from 3.0 to 3.1.3

[indossatrice]

Can someone please help.. I want to upgrade my unlocked/jailbroken iphone 3g from the 3.0 firmware to the 3.1.3.. can someone please list the steps in doing so? I already downloaded the firmware.. now I'm stumped.

[Applejuiced]

Use pwnage tool to create a custom 3.1.3 ipsw and then restore to that thru itunes.
If you update to stock 3.1.3 you will lose your unlock so be carefull.