Hi Kali. In the Cacti & Succulent forum search for “beheading” and you should find several posts on this topic that should help answer any questions.

Short answer is, yes you can. But you will want to cut it off and let the end dry out before sticking it back in the dirt. Then don't water for a while until it starts to establish roots. You can also leave the other stalk there, trim it down, and it will start to sprout leaves.

I do not think it will get upright enough at this point. It may be quite top-heavy, and you would most likely have to keep it supported. It may be best to decapitate/behead. You could leave stem with just couple of leaves (or more) potted, and it may start growing offsets. I don't know if it will grow just leaves. Most plants grow offsets from stem, not singular leaves.

I would cut it where the red line is, or below next set of leaves - not any longer: