How do you get classic knuckles in mugen?

To get Classic Knuckles in M.U.G.E.N, you need to find a character file for Classic Knuckles, often available from M.U.G.E.N character repositories or forums. Once downloaded, extract the files and place them in the "chars" folder of your M.U.G.E.N directory. After that, edit the "select.def" file in the "data" folder to include Classic Knuckles in your character roster. Finally, launch M.U.G.E.N to play with Classic Knuckles.