Insert a screwdriver into the screw end that sits flush against the wall. Turn the screw to the left. The screw backs out of the wall while unscrewing from the toggle on the other side of the drywall. When you remove the screw, the toggle piece falls down inside the wall. Use drywall patching compound to fill the small hole left from the screw, and touch up the wall paint to cover the repair.
Unscrew the screw from a molly bolt in the same manner, and remove the screw. A molly bolt is similar to a toggle, but some of it remains in the wall as a solid cylinder. Tap on the remaining visible part of the molly bolt with the round end of a ball-peen hammer. This gently smashes down on the metal bolt, collapsing the drywall around it in a round depression.
Fill in the depression with a generous amount of drywall patching compound, creating a raised area where the depression once was. Allow the wall to dry completely. Sand the patch so that the area is completely flat. Cover the filled hole with paint to match the rest of the wall.