With extreme patience! They will take 7 years from seed to flowering size bulb. Good luck...they are well worth the wait.
I wonder if you'd know what to do with the little seeds? Should I plant them in soil and when? Where might I find more info?
Check out this site. All the info you need is here. http://www.pfaf.org/database/plants.php?Cardiocrinum+giganteum
I have had good success growing Cardiocrinum from seed. I planted the seed in #4 mix covering the seed with fine grit. After placing them in my cold frame, they germinated the following spring. Last year the first one bloomed(6 yrs.)