Believe it or not Eddie, you don't have to do much. The worst part is over. They didn't eat the eggs, they didn't eat the free swimmers, they attached and now all you have to do is get them feeding off the parents when the time comes and you're just about home free. Two culls and you have saleable fry! For your first spawn, you are doing great! LOL!
The worst thing that can happen at this point is another spawn and they destroy the current fry.
Best wishes!