Directions:

Launch the appropriate SerialReader for your Macintosh. (Either click on the 68k or PPC reader icon)

If this is the first time you have used the Reader you will be prompted for a Serial Box data file location.

Click on the button and browse and select the Serial Box data file you wish to open and view. The preferences will be stored in the same folder as the Reader application. Once you have selected a Serial Box data file location the location will be remembered each time you run the Reader.

Other preferences and the use of the Reader software are easy to learn.
There is no "manual" for the software and there is no need for one to be written.
If you can't figure out how to use this software then you really should not be using serial number files to begin with.