There's 2 ways that I know of to get ESPN3. Either have an XBox 360 with a XBox Live gold account and watch it using the XBox, or your internet/TV provider has a deal with ESPN3 which will allow you to view the race on
www.espn3.com. All of the American Le Mans Series races are kept in an archive on the ESPN3 website, so you can watch the whole thing any time if you want.