Always use the stripped screw extractor with the reversible drill at low speed in a counter-clockwise motion.

Step 1: Select a bit size for the screw you want to remove;

Step 2: Chuck the bit into your drill driver, switch the transmission to counter-clockwise, check the rotation, and drill a hole in the center of the screw head, go at the slowest speed you can whilst still cutting into the old screw and select the smallest possible size extractor bit.

Step 3: Flip the extractor bit and adjust the extractor side of the bit in the hole, switch the transmission to counter-clockwise, check the rotation, make sure the extractor locks in the screw; otherwise, change to the next size.

Step 4: Slowly remove the screw using a drill driver while applying moderate pressure.

There you go, you got screw out like a treat !