Should you remove the sac from a newborn kitten?

The mother cat will bite, chew, and eat the sac. If she takes too long, break the sac away from the kitten's face. But otherwise, let her finish doing it. Her licking stimulates the kitten to breathe. IF mother is in distress, grab a rag, hold the kitten inside the rag using both hands and vigorously rub to remove the sac and stimulate the kitten to breathe--then take mom and ALL kittens to the vet.