Maybe, the metal tip sticking out the top has threads that screw into either the big triangle support or a very little small profile "T" nut. Construction of the receiving side directs the choice between the two.
Maybe, it would entirely depend on the diameter and height of the leg. The shorter and wider the leg the better. I would NOT only rely on the small fastener joining the leg to the frame.
Maybe, The other side of the fastener (Hanger bolt) has a wood type threaded end that is deeply embedded into the leg. You would need to use 2 nuts that fit the threads sticking out. Then place the leg in a vice carefully so the leg is not damaged (leather, heavy cloth, greenie pads etc.): or find someone strong enough to replace the vice. Screw both nuts on the exposed threads; using a wrench that fits the nuts unscrew the nut closest to the leg ONLY. That will cause the lower nut to "Jam" into the nut above. Now the fastener (Hanger bolt) "should" unscrew. The problem is there may be some kind of cement adhering the fastener to the wood. They MAY NOT come out.
5.75 " high
The widest part of the leg is at the top by the bolt. I just checked several and they are 1 3/8"
Ohiolyons, This leg comes with a 5/16-18 hanger bolt. Thank you, Zac