How to open: Instead of pulling the hoop open, apply slight pressure with your nail where the post meets the back.  By doing this, you can avoid reducing the friction that holds the hoops together. 

How to close: Gently pinch them closed until you hear a click.

Because of the delicate nature, over time and though changing out your earrings often, you may find that the post becomes misaligned with the back.  If this happens, it’s an easy fix.  Simply adjust the position of the post by applying slight pressure up or down until you hear them click again.