https://www.youtube.com/watch?v=5rjqvG0FXXM

https://www.youtube.com/watch?v=x0GUQFAyP_Y

http://gs3.wonderhowto.com/how-to/network-unlock-your-samsung-galaxy-s3-use-with-another-gsm-carrier-0148738/

Hi this is the best option for me is this if you want i explain here in text i can make for you



http://sim-unlock.net/simlock/Samsung/Galaxy_S3_Mini/