how do i remove my existing oil burning furnace. I understand it is heavy (cast iron) in places.?

Question

how do I remove the plenum

Answer 1

If the plenum is sheetmetal leave it there until you deside on a transition from your new furnace, A-coil, and old duct system. As far as the old oil burner goes. Get a large sledge hammer, some good saftey goggles or glasses, a pair of leather gloves and a long sleeved shirt and take out all your aggressions on it. The smaller the pieces the easier they are to carry outside. No joke! Also, don't just throw in trash. A local scrap yard should pay pretty good price for cast iron. Not like copper but usually worth the trip.

Answer 2

Twenty pound sledge hammer.