You will need...
All that lead, a plumber's pot lead melter (no sense fooling with a couple pounds at a time) at the top of a twenty to thirty foot tower or platform, a pool of water about a foot deep and wide enough to catch all the drippings, an aluminum (melted lead will not stick to aluminum) colender (sort of like a strainer) and some heavy duty heat protection gloves (the aluminum will be as hot as the lead). You will also need a lead particulant mask (available at most hardware stores - make sure it is rated for lead particles) and face/head/body protection from lead spatter.
You will learn by trial and error. You can re-cycle the mistakes, but be careful putting the lead back in the pot; if you dump a piece with water on it, the water boils instantly and flings molten lead in all directions.
You'll probably get a range of shot sizes, and you'll have to figure out how to sort it. Some sort of progressive screen (start with the small sizes) and much shaking or rocking. Perhaps you can adapt one of the media tumbler extractors?
Actually, this sounds like a fun project. I may try it myself when I retire.