I got the M8 thread repair kit. It can be difficult to find the exact drill bit and tap needed for M8 helicoil inserts. You probably won’t find them in a standard drill bit set or tap set. This thread repair kit makes it easy by including the exact size of drill bit and tap necessary. 

The kit is very easy to use. First, drill out the damaged thread, use the tap on the newly drilled hole, thread in the helicoil insert using the included installation tool, then break off the tab using the included tool. It took my less than five minutes to complete a repair.

This was a nice less expensive alternative than your local parts house. This tool is well made and makes setting thread coils very easy, then remove unthreads right back out with ease. Easy to use and works as it should. Then simply remove it easily

Excellent product and super easy to use for my Cruze 2014 on the valve cover and the block

Bought the M8 size rethread kit and it worked perfectly. Had to rethread 2 bolt holes in my cars thermostat housing which was a risky job but Got it done easily! The hardest part was trying to hammer out the little wire at the bottom of the coil, i gave up and just started bolting. Would buy again if necessary

M8 x 1.25 mm Thread Repair Kit with HSS Drill Bit and Inserts