If you have the right tools, then almost anything is possible. Without the right tools, it takes elbow grease, if it is even possible.
So I'd use my reciprocating saw, with a metal cutting blade in it. Lacking that, I might pull out an angle grinder, or an air powered cutoff tool. You need not even cut the pieces completely through. Just cut it most of the way, and then bend it a few times to fatigue the stub of metal that remains. It will break then easily.
Lacking any of that, now I'd be left with a hacksaw, and elbow grease. Use a good blade and it will cut faster.
You can either cut the tubing into pieces, or cut away the screws that hold it together. Sometimes one or the other is easier. And sometimes disposal companies don't like to take long sections. (Ours won't take anything longer than a few feet.)
No matter what you do, wear good strong gloves, as old rusty pieces of metal will be hard on hands that are not accustomed to such work. Safety glasses are a good thing too, as pieces of flying rusty metal are not good for your eyes.
Lacking even that, I'd have no choice but to pay someone else to take it away, or let it rust away in place. A hundred years from now, and it will be mostly gone on its own.
Note that if you can easily enough bring the steel to a salvage yard, you may even salvage a few dollars from the scrap.