Assuming that I could keep my hormone-addled mind out of the gutter, I would gather data and notes to help further the new sex-changing technology. Duh.
I would probably want take up super-science myself and stick with the researchers for a while. Screw this irreversible life-changing transition nonsense, I want to get it to the point where I can switch back and forth indecisively every morning like I don't know which shirt to wear.
I would probably freak out upon encountering the whole brain-washing thing, though. It raises so many questions! Did I really agree to the procedure, or was I kidnapped and brainwashed into thinking I had volunteered? In fact, wouldn't it be easier to just trick me into thinking that I've been male up until now, and then neuralize me again at the end of the week? What guarantee would I have that they don't plan on messing with my mind for much longer than that?
AAAAAAAAAAAAAA!
My options would include a daring escape across the border or a confrontation with the mad scientist that created me as I am now. The former is easier, but ultimately I would face my fears and go back. It would turn out that the procedure was real after all, but his/her/its master plan is to deprive humanity of all static identity, rendering us indistinguishable through infinite variation, like a sort of living white noise. It would turn out that my adversary read the evil overlord list, though, so I'd be dead before hearing the part where this actually helps to take over the world.
...I guess this is why most of you kind of glossed over the brainwashing part.