How Do I Make A New Bar Of Soap From The Ends Of Old Bars?

I have the ends of various old soap bars. Much of it expensive gift soaps. How do I melt ‘em down and squish ‘em together to make an new bar of soap?

How Do You Make Soap Out Of Bacon Grease Or Fat? Or Any Leftover Fat From A Greasy Meat?

Sometimes I make bacon or chorizo, and I have leftover fat. I was told that you can make soap out of fat. So I just wanted to know how.