This may be useless advice, but I'll try.

First of all, dance.

Dance whenever you've got the opportunity. Make the opportunity. Dance while listening to the music that's played on the telephone while you're on hold. Dance while waiting for the bus. Dance until it comes so naturally that you're tempted to pick up your instrument and play along while you're dancing.

Then do it.

By the way, John Hartford does just two different steps, so don't worry about getting fancy. If you dance because it's fun, and love it when people dance and play at the same time, then you'll learn how to do it to, within a few years. If you love it, it will come.