The unitypackage file contains*:

Textures, PSD file has Black and Leather variant as layer
The KD León Jacket Model and its .blend file
Blendshapes for both Breathing and BreathingBelly, Blendshapes for Female and Muscle body types, Blendshapes for opening and closing the KD León Jacket, Blendshape thickening the KD León Jacket, Blendshape for FurCollar(disable its PhysBones when enabled) and a (seemingly universal) Blendshape to wear a plate carrier under the KD León Jacket.

Applying instructions (ApplyAccessories Only)

Place the KD León Jacket prefab inside the avatar that you are working on, do this by drag and dropping the prefab from the project file, then drop it into the avatar in the hierarchy window.

Move the prefab outside the avatar, unpack the prefab, move the PhysBones game object outside of the León Jacket prefab.

Use Standard to automatically parent the clothing to your avatar with Don't Reuse Bones turned ON.

Put the PhysBones game object back in the KDLeonJacket game object the ApplyAccessories moved it inside the avatar for you.

Set the Root Transform for the PhysBone found under Physbone>FurCollar to be Chest_KDLeónJacket, located under the chest bone of your avatar.

MOCHIE shader is required for the MOCHIE preset.

POIYOMI shader is required for the POIYOMI preset.