I have an iPhone 3GS 32gb:
Modem Firmware: 06.15.00
Serial Number: **9425S13**
The phone is currently jailbroken and unlocked at iOS 4.1 (8B117).
How can I upgrade the phone to iOS 5.X, to a untethered-jailbreak-ready and unlock-ready state?
I have tried an iTunes standard update on a dozen different computers but I always get some sort of error; usually 'this device is not eligible'.