I'm sorry for your loss and the other injured birds.
I would start by cleaning their wounds, stopping any bleeding with styptic powder, cornstarch, or flour, and putting antibiotic ointment or a wound spray (like blue kote or veterycin) on the wounds. Make sure they're in a clean, warm place, too. Offer water with vitamins/electrolytes in it if possible and give them any food they will/can eat: moistened chicken feed, mealworms, fruits, vegetables, applesauce, yogurt, etc. You may need to force feed or tube feed and water any of them with faces/beaks too severely damaged to eat on their own. If the damage seems too severe or a bird seems really in pain, humane culling would probably be preferable.
With such severe injuries as it sounds like your hens have, they should also get antibiotics to help prevent infection. Tylan50, Tylan200, Baytril, and oxytetracycline/terramycin are all possible antibiotics. Due to new laws, though, most antibiotics need to be purchased with prescription from a vet, so you may need to contact a local vet and ask if they can prescribe anything for you.
Chickens can live with beak and face damage, depending on each bird's resilience, care, and condition. This is one story of a hen who lost a major part of her beak and lived:
PLESE HELP!!!! Chickens beak got bit off