Epson DLQ-3500 Setup Manual page 12

5. Remove the new ribbon cartridge from the package and turn
the ribbon-tightening knob in the direction of the arrow to
remove any slack from the ribbon so it is easier to install.
6. Hold the ribbon cartridge with the part where the ribbon is
exposed facing down and the ribbon-tightening knob facing
the front of the printer.
As shown below, guide the ribbon under the print head, and
snap the cartridge into place from left to right so that the tabs
on both sides of the cartridge fit into the notches in the
cartridge holder.
10
Setting Up the Printer