I'd get some good sawzall blades and go for it. really doesnt take that long since your ripping thin metal. way less chance of a fire too though if its fuel oil it has less chance of an explosion than say gasoline. Mine had some sludge and a small amount of liquid and I cut it with the sawzall. then lit newspaper and burned out the sludge. stinky and smoky but didnt take long. putting water in it is a good idea.
2010- 5 taps -Fish Fryer
2011 - 2013 - building up
2014 - 192 Taps on gravity, 2x8 flat pans on homemade evap.
A wife who doesnt shop and lets me buy Maple stuff