Save these files into your Autodesk Template directory so you can create a new drawing using these templates.
Steps to add these files to your standard template location:
1) From AutoCAD, select 'New Drawing'
2) The default template window should show up showing you a list of available templates.
3) Copy your newly downloaded template files, right click in this window, and select 'Paste'.
4) Now your new templates are ready for you to use every time you start a new drawing.