If you haven't already started an adventure you can delete the old one by pressing b+select+up. You have to press them at the same time on the Main Menu screen of the game.
Start a new game
erasin the game
Up,select,b
press new game button on starting menuu
All your previous things will be gone forever
Neither. The new game is called Soul Silver, not Silver Soul.
press b+up+select at title screen
Start a new game, or cry about it.
When you start soul sliver press pokewalker and choose you Pokemon and connect it to you ds then Wala!
Heart Gold and Soul Silver
To delete your poke walker data you must start a new game in Pokemon Heart Gold/ Soul Silver.
Uh how about buy a new game.