To update the firmware on your Blackberry you need to install Blackberry Desktop Manager to your PC.
Connect your Blackberry to the PC and it was prompt you to update.
Once you have it installed on your computer, simply connect your tablet to your computer and open Black Berry Desktop Software, then click Update.Please note that until the update is complete, you will not be able to use your Black Berry smartphone.Should you unplug or cancel the update process before completion, your smartphone may be unusable and you may need to restart the update process to regain use of your device.But for those who've made the switch from Black Berry 10 to the Priv, the procedure is understandably new. Once your device finds the update, you'll be asked to download the 463.6 MB update by tapping on the Download button.You can either continue using your device until the download finishes, or leave it on this screen.
You will not be able to make or receive calls or text messages until the update is complete.