First, go this this page and follow the instruction on finding the MEP code. And once you get the MEP code, go to this site and paste the MEP code along with the IMEI. Once you click calculate, you'll get this message:
Mep2(NCK) THIS IS YOUR UNLOCK CODE: 00000000Mep4 YOU MAY NOT NEED THIS CODE: 00000000
Depending on which network you're with, you may need to type in both codes
So, how to enter the fabulous unlock code now?
Option - Device - Advanced System Settings - Sim Card
You should see just "SIM Card" menu and it should show ID and your telephone number. Now type MEPD and the menu should expand. What you want to look at is the "SIM" portion. It should say either "Active" or "Inactive." If your phone is still carrier locked, you should see "Active" and if it's unlocked, then "Inactive."
Now the fun part! Entering the code! Type "MEPE" and a small window pops up with "Enter Network MEP Code." This is where you enter the MEP2 code you got.
Go Blackberry! Be Free!