First, try using a shorter screw driver with a larger head. Apply downward pressure and slowly attempt to remove the screw.
This method works best with soft-metal screws.
Note the recommended depth for you specific screw extractor. Don’t make the hole deeper than recommended.
If you are unable to remove the stuck screw, apply a valve grinding compound. This product contains grit that will allow your screwdriver to grip the head. Insert your screwdriver into the head and try removing the screw.