After some effort, I believe I have located a legal precedent. Judge Roy Bean, Law West of the Pecos, once acquitted a man for killing a chinaman. After consulting what law books as were at his disposal, Judge Bean said he could find no law specifically against killing a chinaman in that teritory.
Similarly, I can find no prohibition against the castration of Kofi Annan. In fact, the procedure might actually calm him down, and he could stop humping the leg of every Neo-communist dictator who speaks ill of the USA. I would recommend, however, that he wear dresses, lipstick, and costume jewelry for a period of three months beforehand, so as to smooth the transition.