Acquire these parts:
DEC cable #BCE16E-xx (MMJ to MMJ) (xx = number of feet)
DEC adapter #H8751-F (MMJ to DB25 plug)
Apple Cable M0333 (DIN-8 to DB25 socket)
Set up the terminal-to-slave port as a printer port, and set the speed to 9600 baud. You can also select just the scrolling area as the print area, or the whole screen.
Remember to change DIP switch #3 on bank 2 to "off" on the ImageWriter. The printscreen key on the keyboard is the second from the left on the top row (it is usually labelled) and is functional.