90% of the meat on a muscovy on the breast and legs.
We drop them in a killing cone, cut off their head and drain. Then we hang them by one leg and start
removing their skin. Around one leg, then the other, we loosen/remove the skin. Slice the skin down their belly to their neck and peel the skin towards their backs.
We then lay them on a table to remove their breast meat. Slicing the meat along the center breast bone down towards
their sides. Once both breasts are removed we cut off their legs. 90% of the meat is now off.
Skinning them saves us from eating all the fat, so it's a very lean meat. Beware of the oil gland that is at the base of the tail; where the tail feathers join their back. Avoid that gland!
A year and half old muscovy is OLD for butchering them. We butcher drakes starting at 3 months up to 9 months.
The older they get the harder the skin is to remove and the harder it is to keep the down from sticking
to their flesh.
We use the same size killing cone that we use for our broilers. If they are too large it is hard to get an uncooperative drake to actually stick their head out the hole. They'll pull back their head and you have to sometimes reach up there and bring it down. By 1-1/2 they will also be VERY strong and those toenails are VERY sharp. My DH and I both have scars to prove that. We use leather gloves when handling them.
Hope that helps. If you need ideas how to pick them up without getting beat to death with their wings, I can help there too. They are much stronger than chickens are!