If you’ve got your hands on the Samsung Galaxy S 4G and are desperate to use try it out on another network, now’s your chance as XDA forum member sanfranx415 has found the unlock code hidden in the depths of the popular device.
You’ll need to have root access, a hex editor and some patience and time.
The file to retrieve from your SGS 4G is the bml3.bak file (similar to the Vibrant), which you’ll then need to search for a hex string. The number of results that will return may range from just 2 to 10 and you’ll need to go through each result to find the 8 digit unlock code, (Network Unlock Control Key), for your specific device.
From then on you’re on a home run- just follow the rest of the instructions and before long you should see the magic words ‘network unlock successful’.
For detailed step by step instructions, head on over to the forum thread and follow them carefully!_________