The creators of South Park say they've spent three months to work a grisly Jeffrey Epstein joke into their Broadway hit Book of Mormon.A revised section of a recent showing of The Book of Mormon saw the show creators, Matt Stone and Trey Parker, poke fun at the convicted pedophile. The pair revised the Spooky Mormon Hell Dream song, which sees the main character haunted by the likes of Genghis Khan and Adolf Hitler.Stone and Parker revised the s…