Steps
Get a garbage bag and start picking feathers, don't have to be gentle, just get as many big feathers as possible, leave most small pin feathers, you're going to take the skin off after cooking anyway.
Need a sharp serrated knife, rubber gloves or nitrile throwaways. When transporting, leave one wing and the head until you get home in case game wardens stop you and put in bag separate from picked feathers. Break off feet with fingers, then easily remove them with knife. Break wings at their joints near body (I use a hammer), then cut them off near to the body as possible without damaging flesh. Cut off the neck down to the body. Now for the messy final part: at lower part of body where bone ends, cut gently across the skin on breast of duck an inch or two. Snip off anus at bottom, reach into the cavity and start pulling out innards to throw away. Wash out thoroughly, cook them or put in refrigerator in a pan for eating in a day or so. You can also freeze them (in about 1/3 freezer bag of water if waiting long term-6 months to 2 years, still great).