1)  Compile the program: 'make'

2)  As root, create a symlink from the appropriate serial port device to 
/dev/newton (eg. 'ln -s /dev/ttyS0 /dev/newton')

3)  Make sure you have appropriate permissions to read/write to the 
serial port.

That's all!  You can copy the unixnpi binary anywhere in your path you 
like.
