Here's how to use the Pokéwalker:
1. Connect your Pokéwalker to your DS game. You'll need to have a compatible Pokémon Ranger game (like Pokémon Ranger: Shadows of Almia or Pokémon Ranger: Guardian Signs) loaded on your DS.
2. Choose a Pokémon to send to the Pokéwalker. You can select from your existing team or choose a Pokémon from the Pokéwalker's internal roster.
3. Clip the Pokéwalker to your belt or clothing. It has a built-in clip for easy attachment.
4. Start walking! The Pokéwalker tracks your steps and allows you to encounter Pokémon.
5. Return to your DS game to collect your new Pokémon. When you're ready, you can connect the Pokéwalker to your DS again, and the Pokémon you've caught will be waiting for you in the game.
Please note: The Pokéwalker is no longer produced, so it's quite difficult to find one nowadays. If you happen to have one, enjoy using it!