I brought this up with my vet when I had a roo I just adored, but who sang exuberantly night and day.
My vet sees pet birds and also works on wildfowl that are injured. She didn't want to perform the surgery, and I can't remember exactly why. It either had to do with a poor survival rate, or it had to do with not being able to do it under a local, and she didn't want to use a general. I'm sorry I can't remember the exact reason.
As far as looking for resources goes, I would go to a veterinary university that has a good avian focus and see what is in their library.
Side note - I'm not sure what the laws in your state are, but this may be an illegal operation to perform on your own. Generally operations that are done by owners have to be "accepted animal husbandry practices", like tail docking of sheep, castrating piglets, etc. I don't know if de-crowing would fall into that category or not...