You can pull the whole shoot straight out from the main plant of dirt. Pot it up in Miracle Grow potting soil. Then submerge the pot in water up to the soil line of the new pot. The water temperature must not be below 70 degrees over night to be safe. If you change the water once every month, you will find that Pandanus Amaryllifolius loves water! Since you are in 5b, you can only do this during the summer months. If the offshoot is attached to the mother plant above the soil line, you should wait until you see aerial roots attached to the offshoots. During the spring and summer, submerge the pot to encourage roots formation. The offshoot that forms in the soil is coming from the roots of the mother plant. You can pull those up with roots attached to them. Again, the best bet is soak the pot, then pull straight up.