There's a difference of opinion as to whether being transgender is haram; see my answer here. An example fatwa which says it's haram is:
We know, therefore, that these operations are prohibited and that no one from among the scholars whose opinion is considered permits them, save with the exception mentioned in the council's response. -- Dr. Hatem al-Haj, Assembly of Muslim Jurists of America (AMJA) (Fatwa 22813, 2007)
Some transgender people undergo sex reassignment surgery, where the reproductive organs of an individual are surgically altered to be (more) consistent with their gender. It's not considered a reversible operation, e.g., vaginoplasty includes amputation of the penis and testes.
Suppose a post-operative transsexual accepts such fatawa and thinks they've made a mistake and wants to correct it. I'm wondering how they would go about making amends.
Question: According to scholars who view transgenderism as haram, what should a post-operative transsexual do?
Ordinarily, by the time they get to the point of surgery, transgender individuals will have established themselves as their identified gender, and have probably undergone many other medical procedures. They do this because they genuinely believe they are of the gender they identify with.
It may be that these scholars suggest to reverse all this to the greatest possible extent. Or perhaps the impracticality and reduction in quality of life makes it recommended to stick with the identified gender.