Or you can condition them in the tank with divider in the middle and separate them by their sex. Especially the clear divider which they can see each other but "no touching". And pick the ripest female and bmost briliant colored active male which is one of the dominent male in the group. And believe me the male color become more brilliant color, especially blue when they are competing for female.
And set them up for the private room(small tank, container 1gallon ~ 10 gallon would do fine). You don't need to put anything like filter or heater as long as water stay 70~75F would be fine. Maybe slow air stone and some plants like Java moss or some rooty floating plants like water lettuce or water hyacinth or even some spawning mop. And put the pair in the tank in afternoon or evening, and they should scatter the eggs in the morning within 2~3 days but most likely next morning. You just need to make sure the eggs have some protection or remove the breeder as soon as they are done. Which you can tell by some small clear tiny eggs on the floor and no more chasing of female by the male. And female should be really skinny and almost looks like you have 2 males after the spawning.
And some say, Neon's eggs are light sensitiveso you might want to cover the tank so they are in the dark. They would hatch in 24 hrs or so depends on the temperature. But first day, they are almost invisible since they are clear and small and not move much. They need another 2~3 days to become free swimming which time you need to start feeding with really small food. Green water or some squeezed water from established sponge filter. Or you can buy some baby food from the store but they are pretty much made out of the hard boiled egg yolk.
And you can move up thier food to microworm or vinegar eels and newly hatched brine shrimp. About 30 days, they will show their neon stripe.
Transform from the brown tiny fish to neon lined tiny fish.
It is such a pain-staking things to do for such an inexpensive fish. Since they are sold for few pennies from some Asian Country if you are willing to buy several hundred to some thousands.
So there are no financial gain here but you feel some accomplishment. And if you can breed Neon, you can do most of the other tetras. Good luck.