How to Unlock Your iPhone Using SAM ( iPhone 3g, 3gs, 4, 4S) guide.
Step 1: Go to Cydia, add repo.bingner.com as an app repository, and then search and install Sam Bingner’s Subscriber Artificial Module (SAM) package.
Step 2: Launch SAM by tapping the SAMPrefs icon.
Step 3: Go to utilities, and then select “De-Activate iPhone,” but make sure the iPhone is deactivated under “More Information.”
Step 4: With SAM enabled, select the “By Country and Carrier” in “Method,” and then find the iPhone’s carrier.
Step 5: Go to “More Information,” copy the International Mobile Subscriber Identity (IMSI) in SAM Details, and then tap “Spoof Real SIM to SAM.”
Step 6: Return to the main SAM screen, change the “Method” to manual, and then paste the copied IMSI string.
Step 7: Connect the iPhone to a computer and allow iTunes to essentially re-activate the device.
Step 8: Double click the “Phone Number” parameter in iTunes to check and ensure the ICCID matches the SIM card. Repeat from Step 1 and onward if it does not match.
Step 9: Disconnect from the computer, and then quit iTunes when the reactivation process is finished.
Step 10: Disable SAM in the SAMPrefs app. Ignore the source article that instructs to uninstall SAM and delete the lockdownd folders.
Step 11: Connect the iPhone to the computer again. iTunes will appear and claim it cannot activate the iPhone.
Step 12: Close iTunes, and then open again. Upon launching, iTunes will activate the iPhone. The result—one unlocked iPhone!
Note: The iPhone will only work with the SIM card employed during the above tutorial. After completing this process, iTunes will believe the SIM’s ICCID belongs to the original, intended carrier. The newly unlocked iPhone can even undergo reboots without losing its unlock— at least until Apple releases a counteracting firmware update.
Also, if push notifications stop working, open SAM, select “Clear Push,” and then connect to iTunes again.