1. Request your unlock code through doctorSIM.
2. Turn on your BlackBerry without a SIM card inserted.
3. Access the main menu and go to Options -> Advanced Options -> SIM card.
4. Activate a hidden menu by typing MEPD.
5. Now type MEP2.
6. You should now be prompted to enter the unlock code you received from doctorSIM.
Your BlackBerry has now been unlocked permanently so you can use it on the carrier of your choice.