The open-faced spin-casting reel is different than a closed-face spin-cast reel in that the reel hangs under the rod rather seated on top of it. Also, the line is exposed rather than contained inside a plastic or metal cover.
To cast, hold the rod at about waist level, grasping it so that the reel is below the rod, and the stem of the reel feels natural between your fingers. The bait or lure should be hanging 10 to 18 inches below the end of the rod.
Hook the line with the forefinger of your rod hand and open the bail, continuing to hold the line with your hooked finger. Finally, pull the rod tip back so the tip sweeps over your dominant shoulder and bring it forward swiftly, pointing the rod tip at your target.
As the rod comes forward of your shoulder release the line with your finger so the weight of the lure pulls line off the reel. When the lure lands close the bail with your hand, and you're ready to reel.
Watch this video to see just how it's done.