Apple have launched the latest firmware version 3.1.2 for iPhone, but I can’t update to this version due to the Sim Lock.

I have successfully upgrade mine from Version 2.2 to Version 3.0 today.

The simple step as below:-

***DO IT AT YOUR OWN RISK***

***BACKUP YOUR DATA 1st, ALL YOUR DATA WILL BE REMOVED AFTER UPGRADE***
1. Download the iPhone 3.0.1 Firmware

2. Open the iTunes, when it prompt to update version 3.1.2, just ignore. Then Hold your Shift (for Win PC) or Hold Option (for MAC) when click Restore button, browse to the downloaded firmware and continue the restoration process.

Your phone will be reboot.

GOT YA!!! you phone is now TOTALLY BLOCKED! you can’t do anything!!! but DON’T PANIC. (but I do until I found out how to fix it).

3. Download redsnOw 0.8
- For Windows
- For MAC

4. Download Jailbreak Firmware (NOTE: filename is different from the 1st one u downloaded)

5. Run redsnOw and browse to the Jailbreak firmware and follow it instruction. (NOTE: if the screen stop at Reboot Device, just unplug the USB cable and plug it back)

After Step 5, your iPhone will be functioning now, but you still can’t connect to your Telco, until you complete Step 6 & 7.

6. Once the step 5 complete, goto Cydia, and install updates.

7. Once the update is done, goto Cydia again, and install ultrasnOw

8. You’re DONE! your phone should work as normal now!

Hope you enjoy the fun of DIY.