Fujitsu DL6400Pro User Manual page 27

Installing the Ribbon Cassette
3-4
4. Align the pins on both ends of the ribbon cassette with the guide
grooves inside the printer. Then press the ribbon cassette down to
install it.
Ribbon cassette
5. Hook the ribbon over the ribbon guide.
6. Turn the ribbon cassette knob clockwise to remove any slack.
Ribbon
Ribbon cassette
7. Close the top cover of the printer.
Ribbon guides
Pin
Guide groove
Knob
User's Manual