How to jailbreak and unlock iPhone 4 IOS 4.3.3
To unlock iPhone running on IOS 4.3.3, it should be first jailbroken using redsnow 0.9.6rc15 which was developed by the Dev team in May 2011 and then unlocked by installing UltraSnow 1.2.3 via cydia. Below are the detail steps for jailbreaking and unlocking iPhone IOS 4.3.3: