Robot to human

[DwarfPriest]

Two obscure gaming references, though no process is shown.
Megaman: In the original series, it's said that somewhere between Megaman 3 and 4, both Megaman and Protoman become human through some weird machine. Megaman is, then, forced to be made into a robot again to fight Cossac. Protoman's change would have made him get a change of heart and decided to help Megaman in MM4 (before they retconed it to a fake Protoman fighting Mega all this time, in MM5).
There is a scene with Megaman entering a machine and coming out with his armor, though. I think there's another like that in one of the SNes games, as well, though that one he is just putting on his battle armor.
Bomberman:The original Bomberman game had the following storyline: The main character is bomb-making robot, that works in a factory. He hears about tales that if one escape to the surface world, he'll be granted a wish, so he fights his way out to freedom, and he would use said wish to become human.

And who can forget 18 from DBZ? Well, to tell the truth, I never understood that part very well...