Step 4: Soldering
Solder each pin to the board. My board had two power rails running up the center of the board, so I soldered the positive pin on the uln2003 (see schematic from here and pictured below) to the one of the rails and the negative pin to the other rail. Then, you must solder pin 2 on your parallel port connector to pin 1 on the uln2003. Solder pin 3 on the parallel port to pin 2 on the uln2003, pin 4 on the parallel port to pin 3 on the uln2003 and pin 5 on the parallel port to pin 4 on the uln2003. Now solder pin 25 on the parallel port to the negative rail on your circuit board. Now, solder the motor to the driver. Hooking up the motor to the board requires some trial and error. I just soldered wires so that I could use alligator clips. You could also use screw terminals or something similar. Simply solder a wire to pin 16, 15, 14 and 13 on the uln2003. Then solder a wire (preferably black) to the positive rail. Your driver is almost done. Finally, solder your barrel jack (I recycled mine from an old RC car) to the power rails on your circuit board. To prevent my wires from breaking off, I put hot glue over them.