This type of earring is suppost to be difficult to remove. It's got the little notch in it near the end of the stem. Hold the decorative end and gently pull the other end while twisting. You'll have to "pop" it out of that groove.
If your ears have been pierced for several years then you just hold your lobe and use your other hand to grab the clip and pull off. If it is a recent piercing, use ice to numb the lobe and then pull off the clip.
grab the earrings with pliers and jerk REAL HARD. If it was a pair of studs that you have had put in then they should just pull off without too much hassle.
Clutch earrings have a hinge-spring clip. To remove the earring, grasp the back of the earring with the forefinger and release the hinge-spring by pulling the hinge open.