Cut off the top 10-12 inches of each stem. Remove the lowest leaf on those cut stems. Insert them into the pot below. There is about a 50-50 chance they will root there. There are other ways to propagate, but they are a bit more complicated.
After you have taken the tip cuttings for propagation, you may want to prune back the stems even more. New growth will emerge on any stem starting just below where you make the final pruning cut.
