To do that, you must pick Mario as your character and you will need to visit Hyrule Castle for a phase (you may fight any opponent you need). At Hyrule Castle, Get the preferred opponent to the highest picket platform, and then force him or her off with the platform http://super-smash-bros-nintendo10740.mybloglicious.com/8237429/the-definitive-guide-to-super-smash-n64-cheats