Things You'll Need
Instructions
Insert the "Pokemon HeartGold" cartridge into one Nintendo DS and turn on the system.
Capture a Growlithe in "HeartGold." They are found on routes 7, 8, 36, 37 and 48. According to the Serebii website, the best location and time to find a Growlithe is on Route 48 at night. Growlithes are vulnerable against Ground-, Rock- and Water-type attacks. Catch the Growlithe with a Poke Ball. Alternatively, you can use a Master Ball, which never fails.
Insert the "Pokemon SoulSilver" cartridge into another Nintendo DS. Turn on the DS.
Head to a Pokemon Center in both games. The two Nintendo DS will connect via Wi-Fi.
Trade a Pokemon from "SoulSilver" for the Growlithe in "HeartGold."