Actually I don't think there is anything preventing a female from.being turned into a working male except the law. You can build a penis and a pump will cause an errection and if you transplanted a pair of testicles into her and gave them a blood surplie I don't see any technical problems with getting a production of sperm and an ejaculation from a women, sure the DNA would be that of the donor and its currently illegal to transplant reproductive organs but that doesn't change wether she would be a working he any.
As for making a male into a working female that would be harder because of the structural differences, the number of aditional reproductive organs and the requirements for different hormons to sustain a pregancy