Miss Forcefem's guide on cracking - Femboys
"Femboys" are an often tough shell to crack. The structure of the "femboy" as an idea acts as a spiked shell, both "protecting" from outside intervention, and keeping the egg in. It's made to absorb transfeminitity in a transmisogynistic context, in such a way as to be comfortable enough to survive in, while being uncomfortable enough to not threaten the statu quo.
I think then that it is crucial to center the "femboy"'s wants, then, as they matter to the body and the world. To press on that discomfort to higlight the contradiction of the self. You want to gently highlight the things he could have, in ways that don't threaten his understanding of himself too much. It's hard and long work.
You can hardly get one to admit that they are or want to be a girl, and it is a foolish notion to press on this first. It is often easier, then, to circumvent the matter to better encircle the boy. Focus on steps of transition, social presentation, hrt. You can obtain often enough a boy that will do many of those and still proclaim boyhood. You can then push on the contradiction of their self, and on the pain that contradiction will cause. If you are close enough to them, you can introduce some transfeminist theory.
Femboys require tact to crack, sadly. They are the product of our society's transmisogyny, and as such are difficult subjects. Yet, do not bear the world on your shoulders. You need not take on more work than you can.