I have a unlocked and jailbroken iPhone 3GS currently using 4.2.1 with 6.15 firmware. I'd really love more than just about anything to be able to update the system to a newer version- is this possible to do easily and safely(ie- not brick my phone)? Are there any pre-existing guides to do this / can someone explain in layman's terms how to do so?
If it matters, I used redsn0w to unlock.
Any and all help is appreciated.
**I did a little poking around and found this- http://www.coolestguyplanettech.com...5-and-preserve-baseband-with-redsn0w/#bootrom
Has anyone used that method? Do you need an ATT sim to finalize the unlock, or will my T-Mobile one do the trick?
If it matters, I used redsn0w to unlock.
Any and all help is appreciated.
**I did a little poking around and found this- http://www.coolestguyplanettech.com...5-and-preserve-baseband-with-redsn0w/#bootrom
Has anyone used that method? Do you need an ATT sim to finalize the unlock, or will my T-Mobile one do the trick?
