How did Nagato gain his Rinnegan?


How was it exactly that Nagato came upon his Rinnegan?

Madara states that it was his, and that he gave it to him: how did he do that?
Did he transplant it into Nagato, or did he transfer it otherwise?

Note: I do not recall whether this was explained in the manga or not.




Well,

> Black Zetsu, which is the embodiment of Madara's willpower and thought
> (Yin), stated that he had indeed _transplanted_ these eyes into him when he
> was a boy. When or how isn't stated, one can only speculate that Madara used
> White Zetsu or some other Zetsu for it.




Well,

> Black Zetsu, which is the embodiment of Madara's willpower and thought
> (Yin), stated that he had indeed _transplanted_ these eyes into him when he
> was a boy. When or how isn't stated, one can only speculate that Madara used
> White Zetsu or some other Zetsu for it.

