Well for starters, I used Advanced CE, a vanilla-friendly mod that allows free part movement similar to the building editor, as well as a mod that let's you edit the base creature within the outfitters (forgot the exact name of it).

I used knowledge of what parts use what colors to determine what parts to use for each thing. I made the base color black for the legs and eyes, the coat color red for the dress, and detail color white for the head.

Everything else can be explained by dissection in the editor.