I had two years of German in college and have some reference books in German that I need to use. Eventually I wanted to learn to understand spoken German and to speak some, too. Books are helpful, but can do only so much.
Step 1: Shortwave radio helped for a time.
For the last few years shortwave service to the USA in German has come to an end. This is because of budget cuts and the broadcasters are changing over to digital broadcasts, but those will not be available in the USA for a few more years.