This sounds grim, but here's what I found on eHow.com:
Steps
1Step OneTie the duck's legs together with strong rope, and hang it so that the head is waist high.
2Step TwoHold the head with one hand and cut the jugular with a sharp knife. Stoop down beneath the wings. Know that the duck may thrash its wing as it is dying. Hold the head firmly downward so that the blood is not spattered about.
3Step ThreeDip the duck in a pot of 140 to 150 degree water, and keep it there for a minute and a half. Move the duck around in the water a bit.
4Step FourHang the duck up again and pluck the feathers.
5Step FiveCool the duck once the feathers have been removed by placing it in a pot of cold water.
6Step SixCut off the head and legs.
7Step SevenRemove the neck by slicing the skin of the neck and cutting it.
8Step EightMake an incision from the sternum to the anus.
9Step NineRemove the intestines intact. Be careful not to pierce them. Just cut them away from the connective tissue.
10Step TenCut out the heart and lungs.
11Step Eleven Wash the carcass and place it in cool water until you are ready to either prepare the duck for freezing or cooking.
12Step Twelve Clean the liver and gizzard. Remove the sack from the gizzard and dispose of it.
13Step Thirteen Remove the oil gland that is at the base of the duck's tail. Again, be careful not to pierce it.
14Step Fourteen Put the neck, gizzard, liver and heart in a plastic back and place it in the body cavity.
15Step Fifteen Place the duck in a plastic bag and remove as much of the air as possible before putting it in the freezer. Of course, these final steps are unnecessary if you are going to cook the duck right away.
Tips & Warnings
Starve the ducks for 12 hours to make the process easier.
Resources
** this last part under Tips really kinda sucks, but if its necessary, at least you have a guideline to go by.
Gwen