A heli coil is a type of repair that involves inserting a small metal coil into a damaged screw hole. This effectively reinforces the hole and allows you to continue using the screw without fear of it stripping again. Heli coils are available in a variety of sizes, so it's important to choose one that best fits the diameter of the original screw hole.
To change a heli coil, first remove the damaged screw and any debris from the hole. Using a drill, make a pilot hole in the center of the coil location. Next, insert the tap tool into the pilot hole and turn it clockwise to create threads. Be sure to go slowly and not over-tighten, as this can damage the threads. Finally, insert the heli coil into the tapped hole and tighten with a wrench until snug.