The route:

The walk follows the Test Way Path with very minor detours and is well sign posted.

 

You download printable pdfs of the 5 main section from St Mary Bourne to Romsey on the link The Test Way | Things to do in Hampshire | Hampshire County Council.

 

Alternatively, you can install the GPX Viewer on your phone and download and open this route file which will navigate you down a very close approximation to the route