The ruling on transplanting a disbeliever's heart into the body of a believer

Question:
Transplanting a disbeliever's heart into the body of a believer, meaning: a procedure in the hospital?

Answer:
This is a matter of scholarly disagreement, and there is no objection to transplanting it. If the recipient acts in obedience to Allah and is sincere to Him, then the faith has moved from a disbeliever's heart to a believer's heart, just as his finger, hand, or tooth is transferred.
Q: Is this specific to the disbeliever?
A: Yes, if the believer needs an organ from a disbeliever.
Q: How does the faith become present in this case?
A: The heart is the abode of faith. The fear of Allah, the love of Allah, and sincerity to Allah move from the bad state to the good state.