Make sure to have 6 faces ready with the sizes of your likings, just make sure there is enough space for the holes and the wiring inside the box.

For the screen and the buttons, you need to respect their sizes while making the holes. For the rest, holes are for wiring so mark where you put your component and then mark the wires' hole right under, make sure they won't end up twisted. We used a drill to make them but you could probably do them with a laser cut.

You can use a hammer and nails to do so.

Make sure they don't move. The sensors and the screen require to use little nails and a hammer. You have to be extremely careful as you might break the components while using the hammer.

Make it like in the picture that you can find above.

Link your computer with your Arduino cards and upload the codes (you can find them above).

That's up to you really.