If you own Garmin GPS unit which facilitates you free map updates, then go to map updates page, from where you can download the Garmin Express. This is a map updater utility which you should install on your computer, in case you haven’t installed it on your computer system. Also, you can follow the instructions given there to install and set up the Garmin software for updating GPS maps. In case you don’t have option for a free lifetime map updates then buy Garmin street map updates from here. It gives options to buy the street map as SD card updates, or as downloads. For simplicity and ease of use you opt for the SD card updates.