Click here: http://software.garmin.com/en-US/express.html
Click on DOWNLOAD FOR WINDOWS (or Mac if that is your OS)
Run the downloaded program to install then open the installed program.
Connect your Garmin to your computer while the program is open. From there, you can update the maps on your Garmin.
If you can take a minute and use the rating system to rate our session as 3 stars or higher and press Submit so I am credited with helping you.