Do we know what they are filled with?
Thinking about it, drilling a hole higher up and put a pin in it to secure the inner billet could enable sawing off the square tube, but it would be more complicated and take more time to do.
Not very likely that the steel is cast iron, would be really bad design, just bring a sledge hammer…
>No body cuts steel with saws
Ever heard of a cold cut steel saw? Find a metal workshop and they can show you circular saws and band saws for steel.
Also, a diamond blade for a cut-off saw (like the stihl) would work but not very fast and blade wears out fast
You need to up your game before pretending to know stuff…