1973 Dart 318 core plug replacement questions

I also use a big screwdriver and a pair of channel lock pliers.
I drive the screwdriver into the plug. **** it sideways. Then grab it with the channel locks and pop it out.
If I don't put a couple of coats of paint on the new plug, I use Indian Head gasket shellac.
Don't overthink this. You don't need OEM plugs. That's what failed. Get brass replacements.
Do not get the flat freeze plugs. Get the cup shaped plugs.
As said flush out the crud. Emery cloth or crocus cloth the hole in the block. Then I usually spray paint the opening.
Time to drive in the new plug. I use a big socket and hammer. If you get started a little cockeyed don't panic. Just tap on the other side of the socket to straighten it up.