It's dead easy to propagate. Any whole leaf will root if you remove it carefully from the stem. Let them float, they'll root and sprout new stems, which can be planted when they have some roots to hold them. Cuttings also root, at the leaf nodes.
I find they do best with decent light and some Excel [or glut], though they will grow without it. Many of mine happen to be growing in tanks with no substrate, and have grown quite long roots from most of the lower leaf nodes. I feed them Flourish liquid fert.