NEED HELP?iphone 3gs 3.1.3 to 4.2.1

[sallmin]

Hi to everyone.I am kind of novice I have iPhone 3gs 3.1.3 baseband 05.12.01 and I wanted to update it to 4.3 or 4.2.1 firmware but I never find how could this be done.If someone could tell me in details how to install 4.2.1 firmware on my iphone then unlock it and jailbreak it I would be very grateful.
THX

 

[OhioLefty]

Hi to everyone.I am kind of novice I have iPhone 3gs 3.1.3 baseband 05.12.01 and I wanted to update it to 4.3 or 4.2.1 firmware but I never find how could this be done.If someone could tell me in details how to install 4.2.1 firmware on my iphone then unlock it and jailbreak it I would be very grateful.
THX

iClarified would be a good place to start. Word of warning, upgrading to these firmwares will not allow you to unlock unless you preserve your baseband (05.12.01). You didn't say whether you are a Mac user or Windows user but the link I'll give you has instructions for both.

iClarified links to JailBreaking

Choose the method that works best for you and follow the instructions. I upgraded from iOS 3.1.2 to iOS 4.2.1 using the iClarified instructions for Windows and it worked flawless. I didn't care about the unlock but will unlock if anyone ever comes out with one for the 05.15.04 baseband.

Good luck and read and follow the instructions carefully!