- Download both files from this guide
- Add the files to "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Xml\Schemas"
- Open a .axml file in Visual Studio, and open Source view (not Design)
- Hit the Xml button in the toolbar, and select "Schemas..."
- Add "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Xml\Schemas\android-layout-xml.xsd"