Take the Eyelash carefully out of the box. Using the adhesive edge that holds it in the box, you can attach the Eyelash to the upper eyelash edge using tweezers or the fingers. Work from the inside outwards, starting slightly inside the inner corner of the eye. Remove the Eyelash again. Any excess length you can cut off at the outer end.
If there is any doubt, it is better to make the Eyelashes 1 mm too short!