An oxy/acet torch is the proper tool. Small hot flame will heat the screw and threads quickly without spreading. Wrap wet rags around the axle exposing only the set screw area. Keep the rags wet. Get a dull red, take it out, check the lube level, put it back using silver or nickel anti seize. Go fishing. Don’t sweat the seals, the water will carry away the heat. This is an old A/C man trick.