Turn your device on, and connect it to your computer with a USB cable.
Or, if your device came with an ANT Stick, turn your device on, and plug the ANT Stick into your computer's USB port.
Download Garmin Express and install it on your computer.
Open the Garmin Express application and follow the prompts to set up and register your device.
From here on, you'll use Garmin Express to install your device updates.