Two forward holes need to be drilled into the components breadboard using a 1/8" drill bit. Use the diagram above for proper placement (top right: 7th column / 3rd row). The back two holes can be marked when placing the breadboard into the plastic box to determine the best location (no traces are affected).
Now solder the Header pins to the MicroControllers breadboard. I found the best way to do this is by using a Project breadboard. Break off 21 pins from the Header strip and remove the spacers. Lay the microcontrollers breadboard flush over the project breadboard and push a pin all the way through each hole on the chips legs directly into the project breadboard. Now the pins are aligned and can be soldered. Use a low-wattage iron and do not over heat. Carefully remove the chip from the project board.
The microcontroller chips breadboard is now ready to solder to the components breadboard. Important: align the microcontroller chip pins to carefully match the proper breadboard holes. Placing a spacer between the two breadboards helps to maintain that the pins are flush with the breadboard. Now flip the breadboard over and solder the pins. Verify that you have no shorts.