I know many people will have a vet handle it because they are too squeamish ... And basically you need to remove ALL the maggots. It's also going to depend how deeply in the tissue they have penetrated. For all these reasons you may want to see a vet.
I have dealt with this in livestock that, frankly, are not the kind you usually take to the vet, such as poultry and rabbits. I flushed the wound with water to help me remove the maggots, cleaned the wound. From there it depends ....
If they are deeper in the tissue they are harder to remove, cause more damage. And you have to worry about toxins being produced. I wouldn't want to say more. A cria is much more valuable than a rooster or rabbit.
Hopefully someone can give you more specific info. In the meantime you might want to let everyone know where the wound is, how deep, how heavily infested, etc. I have seen good outcomes sometimes -- it is very important to treat immediately.