i am starting to fix the brakes on my trail duster. the problem is the rear brake drums seem to be rusted on to the center hub. i tired spraying pb blaster on it and beating it with a hammer,no luck. i tried heating up the drum and then using the hammer again,still no luck. now my back is real sore from wailing on the brake drums all day . anyone have a sure fire way to remove these stubborn bastards?