replacing k&t light fixture wiring
Nearly all of my house's wiring is updated except for k&t running from the switches to the light fixture. Now this is perfectly safe as we all know. However, I would like to add some insulation to the attic and that means taking out the K&T for the second floor light fixtures.
Note that I have no attic access.
What is the best way to replace this wiring with minimal damage to the lath & plaster? I am primarily concerned with how to fish the wire from the ceiling to the wall cavity without making a giant hole at the wall/ceiling intersection. I do not have crown molding in these rooms.
How have some of you all handled this certainly fairly common task?