Transferring old MMJB playlists to MMJB Ver 10

How do I transfer my old Music match Juke Box playlists to MMJB version 10?

I located the old playlists on my computer. They seem to use a M3U extension. However I cannot seem to locate the directory MMJB V10 stores its saved playlists, or to know what extension these V10 playlists use.

Thanks