Clear the damaged thread with a Standard Drill. Up to M12 (1/2") the KITS include the correct drill. To repair a spark plug thread no pre-drilling i necessary if using the special Spark Plug Tap. Please pay attention that for Fluteless Taps bigger holes are requred.
Check that the thread and the pitch of the tap and bolt match
Use the special Wire Thread Tap for cutting the holding thread into the cleared hole. It is recommended to use a suitable cutting fluid (e.g. Templex Blue Foam)
Install the Insert
Place the insert on the Installation Tool and position the adjustable ring so that the insert tang is inserted in the tang slot.
Wind the insert in with a light downward pressure until half a turn below the surface. Don't work against the threading direction as the tang could break
After finishing lift the Instalation Tool and use the Tang Breaking Tool to remove the tang. For bigger sizes and Spark Plug Taps use long nose pliers to remove the tang.
Due to the narrow and exact tolerances the new thread normally is stronger than the original one.