Instructions
Complete the Johto region, collecting all eight gym badges by beating the Pokemon gym leaders in each city, and defeat the Elite Four and Champion of the Johto Pokemon League.
Wait for the credits to roll or just save and turn your DS off and on again to skip them, and start on the Kanto Chapter.
Travel to the Kanto region and beat the gym leaders in Vermillion City, Saffron City and Cerulean City. Head west from Cerulean City and find the Power Plant on Route 10.
Complete the Power Plant side-quest by finding the stolen machine part back in the Cerulean City gym and returning it to the plant.
Continue on through the Rock Tunnel to Lavender Town. Go to the Radio Tower and talk to the Kanto Radio Director,who will give you the Radio Card.
Head East through Saffron City, and beat the gym leaders in Celadon City and Fuschia City. Battle your way up the Vermillion Coast to Route 12.
Find the sleeping Snorlax Pokemon blocking the road to Route 11. Use the Radio Card to play the "Poke Flute" channel to wake up the Snorlax, and either catch it or knock it out.
Enter the cave at the end of Route 11, Diglett's Tunnel. Battle your way through it, and you'll come out on Route Two.
Head north on Route Two through the Vermillion Forest, and you'll come out in Pewter City.