When the flowers are gone, you should find some pods that look like small (but not tiny) slightly crooked cones (or upside-down wasp's nests), that start green and turn pale brown and brittle when they are ready. Then they would start to form small holes near the tip, at which time you just have to turn the thing upside down (carefully, of course, onto a piece of paper or a palm), and you will see hundreds of small fuzzy-looking black seeds (more or less roundish) falling out.
I just did mine today! I pull my fingers along the stalk to be able to get a bunch of dried brown pods in my hands then I cup my hands closely and shake shake shake. All the seeds come out and you can discard the empty pods!
