There is no good way to get rid of them. Your best bet is to feed off your colony and start over. You could remove your kingworms and place them in a new container with new substrate, but you will run a risk of moving the eggs with them.

Working in the pest control industry for 12 years, I have come across this problem in stores and had to throw out all infected food items to get the infestation under control without the use of pesticides.