Play through Hero mode until you encounter the first Great Ape, which will appear in the Rocky Land area (southwest portion) after defeating Captain Ginyu. Fight the Great Ape and defeat it, which will trigger the game to auto-save. You can either fight a random battle on the world map, or change your Super and Skill settings and exit; both will force another auto-save. Exit Hero mode and go back to the main menu, then go back to Hero mode using the same character as before. You can fight the Great Ape again in the Rocky Land area (he should be behind you if you saved in that area), which can be repeated as many times as needed. Note #1: If you defeat 17 and 18, the Great Ape will disappear after beating him. Note #2: This may be fixed in a patch in a later version of the game.