They open at the bottom, just gently push the two ends away from each other.
These earrings are made to order and may vary ever so slightly from the pictures.
Want a smaller size heart hoop? Check out my other listing for 1" hoops: http://www.etsy.com/listing/65771084/almost-seamless-22g-sterling-silver
***The hoop in my ear in the the last picture is my own sample made just for the photos. Your earrings will be made to order, new, and unworn***