Lexmark 4I3 - Manual (Page 193)

4. Slide the print head to the center of the printer.
5. Push the ribbon guide toward the back of the printer and lift the
ribbon guide up.
Note: You may find it easier to remove the ribbon guide by
lifting the right side of the guide first and then pulling up the left
side of the guide.
R ib b o n G u id e
Chapter 4. Replacing Your Ribbon 4-3