I think firm but gentle handling, maybe with gloves at first, just short sessions, then gradually build up. Ignore biting, striking and poop-flinging! I'd keep the little ones a little away from the new snakes until you've had a chance to assess their temperament. We don't want your little herpers to get bitten! Just keep telling them that the new snakes are scared and will be cuddly when they have settled in (we hope!).
One thing to consider, is that these snakes might not settle enough for your little ones to be around, or that it might be months before they do. Only time will tell, but just firm, consistent handling should bring them around eventually.