[Q] flashing bad esn L900 to boost? topic

I would like to flash a sprint note 2 to boost mobile. I am reading up on the boost mobile thread. And I have been reading up on CDMA Workshop. I'd like to use whats recommended in the thread here (DFS). However, I am a little confused and have a few q's.

Do I need a donor phone?

Will this work with a bad esn phone?

Thx!