Get a temp gauge so you put enough heat in but not damage the metal. I think 250F is max I would use. The outer flame tip of your source , move around and go slow. Before you heat screw in moderate preload on the puller so you can immediately see movement. Infra red gun or DMV probes or "tempil stick" welder crayon. If the unit appears corroded try the preload overnight with liquid wrench before heat. In the morning strike moderately with soft hammer (copper, lead). Tighten if possible , strike again.:thumbsup: