You don't, unless you use action replay codes, which you shoulden't
It's only an event pokemon. Check out Serebii.net for details on that
you need a event.
an event from new york.
If you missed the event of celebi for heartgold soulsilver if you have wifi on your ds what you do is go and tap primary code and type in 76-97-173-81
You have to trade it from a 3rd gen game (which gets it from a Nintendo Event).
there is a Nintendo event maybe at gamestop and go to it with Pokemon heartgold and soulsilver and there you will get celibi
From an event.
there is a mew in Pokemon soulsilver but you need to catch all leadndery Pokemon including event Pokemon
A Pokemon from a Diamond, Pearl, Platinum, Heartgold, or Soulsilver event.
You need the event to find celebi without cheating.
Darkrai is an event Pokemon, and cannot be found through normal game play. Darkrai thus cannot be found in SoulSilver. Darkrai was an event Pokemon that was available for Diamond and Pearl, but not for SoulSilver.
its a specal event