Step 4: step3: soldering the wires.
Solder according to the scheme I made in step one. Or you can think out your own if you want to add more 'programs' or don't need to use one.
Once soldered it's actually a working device, so you can check if it's working. Place it in the sun and connect your phone (or something else if you're afraid to fry your phone).
After soldering and checking make sure the wires won't budge anymore. I went a little too crazy with the hot glue, but at least it's sturdy.