Drill out the damaged threads using the drill size specified in the HeliCoil catalog.
Drill to a sufficient depth to accommodate the HeliCoil insert length and the bolt or screw being used.
Tap the hole using the HeliCoil tap. Tap the hole to sufficient depth to accommodate the insert length and the bolt or screw being used.
Place the HeliCoil insert onto the mandrel of the HeliCoil installation tool. Place the installation tool over the hole and wind the insert into the hole until the top coil is 1/4 to 1/2 turn below the top surface.
The tang must be removed to allow full passage of the bolt or screw through the HeliCoil insert. Place the tang break-off tool squarely on the tang of the insert and then give it a sharp blow with a hammer.
For inserts with diameters bigger than 1/2 inch, 12mm, and for spark plug inserts, use long nosed pliers to remove the tang. Hold the tang with the pliers, bend it alternately in and out until it comes free.