Come sblocco Blackberry Curve 8520  
Instructions for unlocking Blackberry Curve 8520

1. Ensure a SIM Card is inserted

2. Go to 'Manage Connections'

3. Click on 'Turn All Connections Off'

4. Go to 'Options'

5. Click on 'Advanced Options'

6. Click on 'SIM Card'

7. Type 'MEPD' (letters will not appear on-screen but a menu will pop up.)

8. Type 'MEP2' (user will be prompted to enter MEP code)

9. Enter the MEP2 code (CONFIRM you get "Code Accepted" message)

i. *If you also have a MEP4 code, type 'MEP4' (you will be prompted to enter MEP code)
ii. Enter the MEP4 code (CONFIRM you get "Code Accepted" message)

10. Reboot device

11. Go to 'Manage Connections'

12. Click on 'Restore Connections'

13. Device is now unlocked