Unlike many modern consoles and handheld systems, games for the Nintendo DS are contained in small cartridges. While cartridges were abandoned for CDs and later DVDs because of their storage limitations, they also possess certain benefits. For instance, if the outer shell of your DS game’s cartridge has been damaged but the small chips that make up the game are still intact, it is possible to swap the shell with an undamaged one to regain access to your game. Opening the shell of a DS cartridge is a delicate process but can be done with minimal tools.
Slide the tip of the butter knife into the slotted end of the DS cartridge.
Carefully twist the butter knife inside the cartridge. This will force the two faces to begin to split.
Place your fingernail in between the two faces of the cartridge when you see the sides begin to split.
Slide your nail up the side of the game cartridge until it has been completely pried open. The cartridge still will snap shut, so at this point it can be placed over the innards of another game.
Opening a Nintendo DS game is not recommended by the manufacturer and could result in the destruction of the game you are attempting to open. Make sure to try this process on a game you don’t mind losing before moving on to one you can’t afford to lose.