You can use the second option from the title screen to enter these passwords; use Up/Down to change the number in the chosen slot, Left/Right to change slots, and Start to enter the password. Note that these passwords will assume you go through Worlds 1 through 6 in consecutive order. (That means left-to-right then up-down on the world selection screen: the top row is Worlds 1, 2, and 3, and the bottom row is Worlds 4, 5, and 6, for the sake of this list.) These are also passwords that will change based on the game difficulty, so choose the one appropriate for your difficulty.