This one had a few fried resistors due to a short caused by damaged isolation from a wire.
I first removed the resistors. The picture above is after cleaning with IPA. The pads are loose but not damaged. The black stuff is burned epoxy. You can see the structure from the, now epoxy-less, FR4 glasfiber. You can pinch a needle through it as if it were cardboard.
This is the other side.I milled away the damaged part, glued in a new piece. I then drilled holes and placed some vias. Then milled the new pads and traces and soldered new resistors in place.
Not very beautiful, but this sort of things are hard to photograph and always look worse then the reality. I could have painted it and use some filler but that is a waist of time. It must be good and that it is.