BlackBerry Desktop Software or BlackBerry Link installed (to ensure the correct USB drivers are present). At least 50% battery charge on the Z3. Step-by-Step Installation Guide Follow these steps to flash your BlackBerry Z3:
Backup Your Data: This process will completely wipe the device. Use BlackBerry Link to save your files.
Flashing Process: The computer should detect the device, and the command prompt will start showing progress percentages. Do not disconnect the cable during this time.