I did a short tutorial on how to change csc on Gear S3 R760. (possible to work with other Gear S3 models)
I'm not an English speaker, so excuse my mistakes.
I'm not a developer, and this tutorial is not my merit. I found the informations here and here.
Do this at your own risk, I do not take any responsibility.
thanks to @adfree
I tested this tutorial in my Gear S3 Frontier R760, Tizen 184.108.40.206, Rom R760XXU2CRC3
I do not know if this tutorial works in any version of firmware but you can try.
1)Go to settings/about gear/ and activate "Debugging"
2)Go to settings/connetion/Wi-Fi/ and set to "always on" then connect to your preferred network.
3)Go to settings/connetion/Wi-Fi/Wi-Fi networks/your connected network/ and scroll down until
you find "IP Address" and save somewhere that address.
4) Download to your Desktop "sdb tool" from here and extract the arhive SDBstarterKidv1.zip,
in the extracted folder you will find more archives.
You have to extract sdb_2.2.60_windows-64.zip if you are using 64 bit Windows or sdb_2.2.60_windows-32.zip
if you are using 32 bit Windows. I will use in this tutorial the version for 64 bit Windows.
5)Navigate to: C:\Users\EMP83\Desktop\SDBstarterKidv1\sdb_2.2.60_ windows-64\data\tools
and launch the command prompt here.
6)Enter 1 by 1 the following commands:
sdb connect 192.168.1.73:26101
after this command you will be prompted in your watch to allow a RSA Authorization Key( you must allow it)
I changed from United Emirates Arab CSC to France CSC.
after this step all your data will be deleted and the device reset to factory settings.