1. Obtain your unlock code through doctorSIM here by simply selecting the Samsung model you want to unlock.
2. Insert a SIM card from another network provider into your phone.
3. Type PIN if necessary.
4. When NETWORK LOCK appears on the screen, type the unlock code you received from doctorSIM and press Confirm (for the following models i900, i8000 and B7610, click on NET at the top and then ACCEPT, and when the PIN is requested type in the unlock code and press ENTER).
5. If NETWORK LOCK doesn't appear on the screen after you have inserted the SIM card from another network provider, enter the following code:
# 0111 * unlock code # (it is normal for dashes to appear on screen while typing the code).