OK, I'll try to reword it.

First you place all the heads, right?
Don't cut circles, use square heads.
Then you copy the background from a file from the game, i e everything but the circles.
Paste this
over the heads, so that the circles are created this way.
Cutting circles are usually bad, as that create a semi-transparent fringe around the picture, which you then fill with magenta, so that you get magenta fringes around the circles.