just remember to keep calling the roos 'dinner' and 'lunch' or something along those lines. It helps quite a bit.
If you know anyone who has butchered before, it is great to have help the first few times.
I actually found a neighborhood boy who hunts squirrel all year round, and he is very happy to come over and dress out any of my chickens for just a plate of cookies. He does a great job, I just show him which one I want done, then go in the house. Way less than an hour later, he hands me one perfectly dressed out chicken, and one trash bag with the offal.
I do let him skin the chickens though, super faster than plucking.
My dad, when he hunted deer, would get the cousins to come over and do most of the work for him, in exchange for a bit of the meat.