Exhaust Manifold Plugs. Stripped and Broke. Heli-Coil?

[BladeX]

I got stock exhaust manifold on there.

And i freakin broke 1 of the 8 plugs. 3 are stripped. and 4 came out fine.

Just gravy. I was reading past posts and people said something bout a heli-coil. I know they sell them at my work no idea what they are tho.

Would i be better off taking the manifolds off and taking them to a shop? Since im n00b? would little metal shrapnel from the drilling affect anything if it fell into the exhaust manifolds?

Anyone know what size of heli-coil id need? And how the hell do ya remove the stripped ones. "Previously stripped" not by me.