Instructions
Insert controllers into Ports 2 and 3 of your Nintendo GameCube or Nintendo Wii system.
Boot the game by inserting the disc and turning on your console. It will automatically go to its main menu.
Click "Vs. Mode" and then "Melee" from the game's main menu. The game will go to its character selection screen.
Hover over the name entry selection for Controller 3. When you hover over the panel that is located at the bottom of the screen, a list of possible names will appear. Scroll down and hover on "NAME ENTRY."
Hover the second controller hand over the "BACK" button at the top right of the screen.
Press the "A" button on the controllers simultaneously. You may have to try this several times; you will know you have succeeded when the game proceeds to the level selection screen.
Choose any level but the "Metroid Prime" level. Once the level begins, Controller 3 will be playing as the Master Hand.