Instructions
Insert "Pokemon SoulSilver" into your Nintendo DS and power on the device. The PokeWalker sends signals to a receiver that is directly inside the game cartridge, so it needs to use the DS's battery to connect.
Press the middle button of the PokeWalker to power it on.
Scroll down on the title menu of "Pokemon SoulSilver" and select "Connect to PokeWalker." This option appears only when a PokeWalker is powered on in the vicinity.