Snap the unit in and and power up the box. You should now be able to change the channels on the converter box from 1 to 99. However most units will take up to 48 hours for the converter to receive system data that will align the channels to the correct channel number. The box must be plugged in and have the input cable connected in order to receive system data.
If the converter stops working properly, unplug the AC cord, wait 15 seconds and plug back in.