Through an action replay code
You can't. You need to trade it from Heart Gold, or get the enigma stone through a wi-fi event
It's from July 31, 2010 to August 27, 2010 in America, Australia, and Europe.
You can find Latias while you're roaming Kanto in Heart Gold, and in Soul Silver you can get a Latias in Pewter City while you have the Enigma Stone.
It's impossible. You have to trade with a Soul Silver game to get it.
Latias is the main Pokemon in Heart Gold. Latios is the main Pokemon in Soul Silver. The only way to get the other Pokemon is to have the Enigma Stone. The distribution event is over so you have to ask a friend if they have it to give to you.
Clefairy......
Magmius or honchkrow
happiny
eevee
you need the enigma stone and go to the museum and talk with the guy what gives you Pokemon from fossils and go outside and a latios appear in heart gold and a latias in soul silver, you can get this item in a Pokemon event or with action replay
fire stone
growlithe & eevee