Contact your service provider, ask for an unlock code. The service rep will then ask you for your IMEI address (you can find this by typing *#06# on the home screen of your phone). They will then contact blackberry who will give them the unlock code, and then email it to you. then follow these instructions: How To Unlock Your BlackBerry For Free
Once you have your unlock code, the process should only take about 5 minutes to unlock your phone. I have done this in the past a few times and it works flawlessly, and its free.