Instructions
Insert the "Pokemon" game cartridge into the game slot on the back of the Nintendo DS game console. Slide the DS power switch to the "On" position to turn on the device.
Tap the "Pokemon" game icon to launch the game. Scroll down to the "PokeWalker" option on the game's main menu screen and press the "A" button to enter the PokeWalker menu.
Press and hold the "Down" button on the system's D-pad, along with the "X" and "L" buttons. This will reset the PokeWalker device and disconnect it from your "Pokemon" save file.