I'm just wondering how transgendered folks show that they have converted and repent that they did wrong. Can they even change their sex back?
(I recognize that this may be a really stupid question)
They never "changed" it to begin with. One's sex is immutably, ontologically stamped upon his or her soul.
Everyone understood that implicitly up until very recently. That's why the sodomite agentists (personified at FE by that disgusting malakos-castrato he-whore "Impy / ClareBrigid / Guacamole") have resorted to using the grammatical term "gender" in place of sex. In so doing they have successfully convinced great swathes of people - explicitly or implicitly - that sex is merely a mutable social construct known as "gender."
Short of a miracle, nothing will restore a mutilated generative member, but a truly penitent sodomite would return to dressing, acting and speaking as much like a normal man as possible. This vile pufta, however, has taken to proudly proclaiming himself a heretic to justify his perversion, and deceptively posting under a new name (identified as "female") in order to continue deceiving well-meaning, ignorant souls... and all with the moderator's seal of approval.
Better for them that millstones be hung round their necks...
As I've said before, this FE rot is the natural result of placing women in authority in matters proper to men.
Sancte Pie Quinte, ora pro nobis.