hmm, i usually kept mine pruned back to make it bushy.
all pieces of stem that have nodes of what you cut back can be used to try to start new plants, rooting hormone and warmth on the bottom and a clear dome to keep the moisture in will help with success.
poke the chunks of stem into some moist potting mix after using a bit of rooting hormone (this isn't a requirement but may help increase how many take). watch for signs of new growth before giving the new plant any normal care.
once in a while i took the houseplants and gave them a shower to get the dust off and it was also a good time to leach the salts out of the pots if they were getting too crusty (and replace the top few inches of potting soil).
i don't recall these plants being heavy feeders and they were ok with being somewhat dry before watering again.
this is all i can remember.
as for this particular plant, take one branch down as far as you want, cut it into chunks of about 6 inches, poke them in dirt and keep it moist (not soggy). once you see new growth you know you have new plants so then you can chop whatever you want of the remaining stems back to whatever length you like.
they should start regrowing from the next node or two down from your cut so it helps to not make your cut more than a half inch or so above a node. this regrowth will likely start before you notice the chunks rooting...