Open the "Archive" folder with Switch Toolbox. (The models for the characters, Pokémon, ETC. are located inside it.)
When you open the files, be sure to look in the "Quick access" folder to find the models, textures, ETC.
Hope it helps!
EDIT: Oh, and I completely forgot to mention:
You'll also need to obtain and extract a Pokémon Sword and Shield ROM.
You can either find one online (I can't link to one because we aren't allowed to do that here.), or dump one from your switch.
When you open the files, be sure to look in the "Quick access" folder to find the models, textures, ETC.
Hope it helps!
EDIT: Oh, and I completely forgot to mention:
You'll also need to obtain and extract a Pokémon Sword and Shield ROM.
You can either find one online (I can't link to one because we aren't allowed to do that here.), or dump one from your switch.