How to Install GalaxSim Unlock on Galaxy S3 for SIM Unlocking

Friday, April 18, 2014

First, make sure your Galaxy S3 is rooted and has BusyBox installed. This won’t work without root access. To make sure you have BusyBox installed, use the BusyBox Installer app from the Play Store to install BusyBox.
Download the GalaxSim app’s APK file from the source page.
Copy the .apk file downloaded in step 2 to your device.
Enable “Unknown sources” under the Settings » Security menu on the device, so that you can install apps from the SD card.
You’ll need a file manager to browse through SD Card. You can install OI file manager or ES File Explorer or any other file manager app from the Play Store if needed.
Open file manager and navigate to where you transferred the APK file in Step 3. Tap on the file to begin installation procedure and it will be installed in less than a minute.
After the installation is complete, run the GalaxSim Unlock app on your phone. When it runs, grant it root access by pressing the Grant/Allow button.
First, select the Backup EFS button to backup your EFS/IMEI data. This is a necessary step as it will help you restore your original IMEI data if something goes wrong.
Your EFS/IMEI data is backed up to the GalaxSimUnlock folder on your internal storage. Do not delete this folder, and also make a backup of it on your computer for safekeeping.
Then, press the Unlock button to unlock your Galaxy S3. After the procedure is complete, reboot the phone, after which your Galaxy S3 will be unlocked for use with any SIM card.

Your Galaxy S3 is now unlocked and can be used with any SIM card of you choice, and you can also install any firmware that you wish to. Do let us know how it works!