There are a few things you should do before starting step 1:
Take the USB drive with the software updates to your vehicle.
Turn on your vehicle, and then turn on the radio.
Make sure your car is in a well-ventilated area. Your vehicle will need to be turned on, with the engine running between 25 to 35 minutes. Make sure that your vehicle is not in Accessory mode.
Plug the USB drive in to your vehicle’s USB port.
Press the media control.
Touch User Device on the Navigation screen. Touch Settings and then Install.
SYNC prompts, “Begin Installation?” Touch Yes on the Navigation screen.
SYNC prompts “Installing file…” Do not remove your USB drive or turn off your vehicle while this update is in progress. Shortly after installation has begun, SYNC says “Installation Complete.” Ignore this message. It refers to a specific phase of the installation, not the overall update process. While the update is loading, SYNC will not recognize your mobile phone or media device.
In another five to ten minutes, SYNC says “Installation Complete.” The system then reboots, which takes several minutes. Do not attempt to use SYNC during this time.
SYNC may also say, "The system will now reboot. Please wait a few moments before using the system."
Your dealer can also install SYNC software updates. There may be a charge for this service, so check with your preferred dealership first.