Instructions
Load the "HeartGold" game onto your Nintendo DS.
Turn on the PokeWalker and press the center button to connect it to your game.
Choose a Pokemon to add to your PokeWalker. Though the Light Ball is meant for Pikachu, you can take any Pokemon with you.
Turn off the DS and clip the PokeWalker to your belt. Walk 7,000 real-life steps.
Reconnect your Pokewalker to your DS. You will receive a Pikachu. There is a 5 percent chance it is holding a Light Ball.
Repeat steps 1 through 5 each day until you get a Light Ball. This can only be performed once per day and may take several days due to the 5 percent rarity.