The worms are probably maggots, fly larvae, and must be removed. For the most part you have to pick them out. This may take a couple of days. Just use soap and water and some tweezers, or even a hose. The wound then needs an antibiotic cream or ointment. Be sure you use one that does not contain a "caine" drug such as cetacaine, benzocaine, etc. You will probably need to clean it and reapply an antibiotic once or twice a day, She should be kept indoors til well so the others don't attack her and so flies don't lay any more eggs in her.
You may end up deciding the wound is too bad and she needs to be put down. I hope it isn't this bad.
