As we know, stem cells can convert to different cells of other organs, can male use their own stem cells to convert it into cells of female-only organs(and vice versa)?
I am assuming you are talking about embryological stem cells and embryological development of genitalia.
The answer is no.
Male stem cells have XY chromosomes. Y chromosome is the sex determining chromosome with SRY gene that determines testes development. Absence of the Y chromosome leads to female development by default. That is why XX forms women and there are people with only one X chromosome which are women. (Turner's syndrome)
It might be possible that SRY gene undergoes a mutation and the gene isn't expressed. There are Y chromosome linked diseases.
You should read up about Y chromosome and development of genitalia.