Start a classic chess match with the opponent set to a difficulty of 6. If you are good at chess, play as white with a Ruy Lopez opening or as black with a Sicilian Defense.
If you prefer to have another AI figure out your moves for you, you can use a chess program online. In the game, choose to play as black, and in the online program choose to play as white against their highest difficulty. When the difficulty 6 AI plays a move, mirror that move in the online simulator and then copy what their response is as your move in the game. This will generate a win approximately 50% of the time, which is far better than never winning if your skills are not at this level.