How to Unlock iOS 4.0.1 on iPhone 3GS & iPhone 3G with Ultrasn0w 0.93

Apple released iOS 4.0.1 yesterday but interestingly the new release did not have updated baseband. Yes, it is same as iOS 4.0 Baseband (05.13.04). This means users can now update to iOS 4.0.1 without involving a risk of getting locked and this has also been confirmed by iPhone dev team member Musclenerd. Users with iOS 4.0.1 can unlock iPhone 3G & iPhone 3GS with Ultrasn0w 0.93.

Previously we posted guides on how to Jailbreak iOS 4.1 on iPhone 3G with Redsn0w 0.9.5 and another guide on iOS 4.1 on iPod Touch 2G with Redsn0w 0.9.5 and now here is a step wise guide to unlock iOS 4.0.1 on iPhone 3G & iPhone 3GS.

Warning: You’re solely responsible for all your unlocking and jailbreaking acts. We bear no responsibilities for any damages arising thereof

Note: T-Mobile USA users must disable 3G before proceeding to unlock iOS 4.0 on iPhone 3G & 3GS.

Step wise Guide: How to Unlock iOS 4.0.1 Baseband 05.13.04 on iPhone 3GS/3G

Step 1: Jailbreak iOS 4.0.1 using Redsn0w 0.9.5 Beta 5. [See here, for Jailbreaking]

Step 2: Start Cydia and go to Manage section

Step 3: Click on sources and click on edit to add following repo:
Repo666.ultrasn0w.com (it is zero and not o)

Step 4: Now search for Ultrasn0w 0.93 and click on install

Step 5: Ultrasn0w 0.93 will take on from here to complete unlocking

Your iPhone will reboot after ultrasn0w completes its installation process. The reboot will unlock your iPhone 3G/3GS 4.0.1 from carrier barrier.