Perhaps you inherited a pair of clip-back earrings from a relative or found a fabulous pair while vintage shopping, but you don't like the pressure the tight clips exert on your ear when you wear them. Instead of wearing the earrings as clips, convert them to pierced earrings to enhance your comfort.
Remove the clip from the back of the earring with jeweler's or needle-nose pliers. Grip the folding part of the clip and remove it, as well as any other parts left behind. Take care when prying the clip away from the back of the earring so you won't damage it.
Rub a piece of fine grit sandpaper across the area where you removed the clip to add some texture to the earring back.
Remove the backing from a self-adhesive earring post and apply it to the area from which you removed the clip, or apply a drop or two of epoxy glue to the back of a non-adhesive post and apply it to the area.
Allow to dry for 24 hours or the amount of time recommended by the glue manufacturer, if you used glue to adhere the post to the earring back.