Blow torch those bitches to the ground lol. Start new. Then start with prevention. You need more airflow. Lower your humidity. Don't spray your plants when it's budding up if your humidity is high. If you feel you can get away with spraying then I use a product called "green cure" as a last resort. I also use h202 mix sometimes. But really the best is prevention from the beginning. Good luck buddy.
And in helping with the pre-vention stages use a good ACT and foliar feed your gurls with it it has been shown in studies and actual use that it helps inhibit PM