Installation- Blender Addon:

Download the Blender addon 

Install the Zip file into Blender through Edit> Preferences> Addons and enable it.

Installation- Substance Painter

Open Substance Painter and navigate to your plugins folder

You can find your plugins folder by going to the top context bar and click 'Python' and 'plugins folder' in that drop down

Once clicked, your file directory will bring you to the 'Python' folder and inside you will see plugins.

Open the plugins folder and drag and drop the Substance_Painter.Py file into it.

Once the Substance Plugin is copied into the folder, you can close it and return to Substance Painter

You will want to go back to the Python drop down you clicked before and click 'Reload Plugins Folder'

Once reloaded, go back to the 'Python' dropdown and you should see a new button labelled with the addon's name.

Click that and the new UI will load into your Substance Painter instance.