We just had central air installed and the contractor removed the radiators. However, the pipe and valves are left over sticking out of the floor upstairs. I tried using a plumber's wrench to at least get the valve off but it would not budge. How can I remove them? Keep in mind that the house was built in the 1930's and removing the whole pipe would involve an asbestos abatement. I rather keep and encapsulate the holes after removing the ends of the pipe with plaster.