Some sites spell it Helicoil, but it shows up as Heli-coil on oreillyauto.com. While Amazon has it for $40.83, O'Reilly and Ace charge $55. Then I need a tap wrench, right?
Schroder 4.006.4 Ratcheting 1/4-Inch Tap Wrench, 3-1/2-Inch Long - T Handle Rachet Tap - Amazon.com. A tap guide would help make sure that my hole is straight:
V-Tap Guide, Metric sizes 1.6mm to 16mm. Finally, I need a drill bit!
Bosch CO2153 13/32-Inch Cobalt SP Jobber Drill Bit
$103.43