Instructions
Collect a sufficient amount of watts. At least 10 watts are needed to access the Pokeradar, which is used to enter battles with wild Pokemon. Walk with the Pokewalker until you've gained 10 or more watts.
Press the middle button on the Pokewalker. Select the option titled "Pokeradar" to allow the Pokewalker to search and scout for wild Pokemon. View the four plots of grass that are now displayed on the screen.
Select the plot of grass with the exclamation point hovering above it using the arrow buttons. The Pokewalker will initiate battle with a wild Pokemon. It will have four bars above its head to denote its health power. Select the "Attack" option to take out one of the Pokemon's health bars.
Repeatedly attack the Pokemon until its health bar is down to one. Select the "Catch" option to toss a Pokeball at the wild Pokemon. The newly captured Pokemon can be transferred to the main game.