well, I know you can get it from Bryan at any of his appearances, and probably directly from him as well, but easier & least expensive might be Elderly Instruments,
it's a Homespun Video product, you can order it from them at
Homespun Tapes. 1-800-338-2737.
Elderly retails it for 33.95, other places probably 39.95, Bryan asks $40 I think, but he'll sign it if you like. He also does workshops, did one hereabouts this past February, check his info for his tour dates.
see the Autoharp Page
and check out the Autoharp Quarterly