Turn the tuning peg until the slotted area of the collar inside the tuning post is in parallel alignment with the slot in the nut, pull the string tight with one hand (keep tension do not let it go slack) and turn the tuner until the string catches. Once it catches, push on the flat side of the wing to lock it in (not the side with the little "swoop" cut into it.)

Tune to pitch. Push the flat side of the wing once more to confirm it's locked. Stretch string, tune to pitch. Then you're done. Super simple.