We now need to attach the cables to the correct GPIO points on your Pi Zero. First, you should detach your cables from your LEDs by disconnecting the poppers. Gather all of the cables together and cut them, so they are all about the same length; make sure that you keep your identification markings on each cable! Now, you can cover them in some heat shrink and apply some heat. Each cable now needs to be stripped and tinned, ready to be soldered on to your Pi Zero.
The diagram here shows you which GPIO point to connect which cable to. Feed all the cables through the hole in the bottom of your Pi Zero case, and then carefully solder each one and snip any excess cable using side snips:
Once we have finished soldering all of your cables to your Pi Zero, we can write a short program to test if they all work. Reconnect your cables to your LEDs, ensuring that you press...