Just reach out via email if your having any issues. If you got two extra standard units just shutdown your full node, plug in the new units to their power supplies and the USB cable to the back of the main unit, fire up the full node and it should auto recognize them and start mining. Keep in mind you might need an extra USB hub if you have more than 2.
If I were to use an extra USB hub, what are the max number of standard units one full package can handle at any given time?