Shut off your ceiling fan. Use a remote control or the fan's pull-string. Flick the fan's wall switch to the "off" position, and give yourself a few moments to wait for the fan blades to come to a complete stop.
Get something on which to stand. You'll need to be able to get a good look at the fan's cylindrical body, so find yourself a chair, ladder or step stool. Make sure to follow any safety directions before you start climbing.
Search the body of your fan until you locate the directional toggle switch. With most fans, this switch is made with black plastic and is typically no longer than a couple of inches. It should be vertically oriented.
Flip the toggle switch into its opposite position. You should hear a click. That'll signify that the switch is firmly in place.
Descend your ladder and push it aside. Don't move it back into storage just yet, as there's a chance you might have to climb back up to your fan in a moment.
Flip the wall switch and pull the fan's string control until the blades begin to turn.
Evaluate the direction in which the blades are spinning. During the warm months of summer, the fan blades should spin counter-clockwise. You may need to stop the fan again and reset the toggle switch if your blades are spinning in the wrong direction.
Check to see whether you feel a breeze while standing directly beneath the operational fan. Your fan's winter setting will force air upwards to displace hot air that collects near the ceiling. Once your fan has been correctly set for summer, the air will be directed downward.