Step 27: Add the strings!
Once the glue is completely dry....
Tie the strings to the hinges. If you purchased commercially available ukulele strings, they will be numbered. The 1st string would be closest to the ground if you were holding the ukulele to play it.
Note: Ukulele strings do not generally go from smallest to largest, like most stringed instruments.
Once tied to the hinges, run the strings through the tuners and start to tighten the strings to hold them in place.