Easiest way to do this:
- Google for "ConvertLIT GUI", and install it
- Install Calibre
- Use ConvertLIT GUI's "downconvert" option (strips the DRM)
- Use Calibre's GUI to convert from DRM-free LIT to LRF for the Sony
The web page for "ConvertLIT GUI" explains the extra step you need to do just once to allow downconverting.