The iOS 4.3 is now out and you could update to it on your Apple device. Don’t forget about the jailbreaks and unlocks while updating to iOS 4.3. If you have any unlock now and want to keep it, then you must not update to iOS 4.3. If you still need to update your iPhone to iOS 4.3, then you could use the jailbreak guide link given below.
Also Read: Jailbreak iPhone iOS 4.3 Firmware
If you are still moving on to updating to iOS 4.3, then here is how to do it.
2. Connect your iPhone/iPad/iPod Touch to the computer.
3. Choose your device from the left sidebar.
4. Press the Shift key(in Windows) or the option key(in Mac OS X), click on the Restore button.
5. Now browse to the iOS 4.3 IPSW file and select it.
That’s it! Your device will now be updated to iOS 4.3.