The general definition refers to exchanging the first and second parts of a proposition, and the commentary also mentions the generality of a conditional antecedent alongside a categorical subject.
This does not permit mechanically swapping antecedent and consequent in every conditional. “If something is human, it is an animal” does not imply “If something is an animal, it is human.”
The four categorical rules are the focus here. Any conditional conversion must likewise preserve truth, and its special conditions require separate care.