PBR Advanced Car Paint comes with a User's Guide in the form of a PDF document.

Installation:

1. Open up your own Blender project or create a new one and click on file, then append.
2. Navigate to where the PBR Advanced Car Paint.blend file is located.
3. Look for NodeTree and inside you can select the PBR Advanced Car Paint node and bring it into your project.
4. You can then use them in the Shader Editor.

PBR Advanced Car Paint also comes with some examples to view in the demo scene which is in the PBR Advanced Car Paint.blend file.