I usually get them at NAPA,Auto Zone, etc.. The kit come with proper drill bit, a tap, 6-8 heli coils(maybe more) and a tool to install the coil into the New threaded hole. Be sure and break the Tang off before installing the bolt. The install tool catches the Tang to screw it in the new hole, should come with instructions.
They some where around $20-$25 bucks for the kit IIRC.
tourbox