Things You'll Need
Instructions
Enabling "Super Smash Bros."
Insert your GameShark cartridge into your Nintendo 64 with the console turned off. Insert any game, other than "Super Smash Bros." into the GameShark, facing forward. Turn on the console and wait until you see GameShark's main menu.
Select "Key Codes" and press "A" on your controller. Use the D-pad to highlight the key code for "Diddy Kong Racing," which must be enabled for "Super Smash Bros." to work with the GameShark.
Press "A" with "Diddy Kong Racing" selected. Press "A" again on the warning screen. Turn off the Nintendo 64's power.
Remove the game attached to the GameShark and attach "Super Smash Bros." facing forward. Turn the console on.
Adding the Codes
Choose "Select Cheat Codes" on the GameShark's main menu. Choose "Super Smash Bros." from the game list. Highlight the "M" master code and press "A" to enable it.
Move over "New Code" and select it with "A." Enter a description for the code using the D-pad to select letters and the "A" button to confirm them. For example, for the Player 1 character modifier to play as Ness, enter something like "P1 Character Modifier Ness." Press "B" when you're done.
Highlight the left box and press "A." Use the D-Pad and "A" to enter the sequence of numbers and letters in the character modifier code you want to enable.
Press "B" on the controller and select "Exit and Save" to save the code. The new code appears with your other "Super Smash Bros" codes. Highlight the code and press "A" to activate it.
Press "Start" and select "Start Game with Selected Codes."