'01 XC70, my wipers have started making noise like an old truck. I want to pull the cowl cover and see whats worn before failure, but the driver's side wiper arm is froze to the shaft. I've loosened the nut and tried tapping it with a hammer while putting tension on the arm but it's close quarters. I don't want to damage the bodywork or windshield. Anyone have a trick to get it loose?