This guide is very simple. With this article, you will be able to see how to upgrade your iPhone 4 to iOS 5.0.1 while preserving old baseband since Gevey SIM can unlock iPhone with baseband up to 4.10..
Note: Do not use iTunes to upgrade your device to iOS 5.0.1 or you will also upgrade your baseband too. If you upgrade, your baseband will be 4.11.08 which can’t be unlocked now.
Download required:
- Download Redsn0w 0.9.10 b3 for here (For Windows, you must be in administrator mode to run RedSn0w)
- Download iOS 5.0.1 for you iDevices from here
- Download iTunes. You can visit Apple site for the lastest version
Now you can follow the guide to unlock iPhone 4 on iOS 5.0.1 with Gevey SIM:
Step 1: Connect you iPhone 4 to PC via USB cable.
Step 2: Start the Redsn0w (downloaded above) then press “Extract”.

Step 3: On the new screen, select Unlock iPhone 4.

Step 4: Now wait for Redsn0w customizing your IPSW file.

Step 5: On the new screen, select “Pwned DFU”

Step 6: Now it is important. Turn OFF and plugged in your device to PC before clicking “Next”.

Step 7: Now you will be one the new screen with guide to set your phone into DFU mode. Follow the steps below:
- Press and Hold Power and Home Button for 10 seconds. Now you can release the Power button while keep holding Home button for another 10 second.
- Now you are in DFU mode.

Step 8: Now you are done with RedSn0w and you can get back to iTunes. You now can restore your device with the custom iOS 5.0.1 ipws which was created above. Do not click on update or your phone baseband will be updated too.
DONE! Now you have updated to iOS 5.0.1 preserving your old baseband. So you can use Gevey SIM to unlock your phone.
You also can follow our guide to jailbreak iOS 5.0.1 for iPhone, iPad and iPod Touch from here.





