Things You'll Need
Instructions
Use your GBA/GameCube Link Cable to connect your Game Boy Advance to your GameCube.
Turn on your GameCube and start a game of Pokemon Colosseum.
Select "Pokemon Trade Machine" from the main menu.
Select the Johto Pokemon that you want to transfer over to Pokemon FireRed.
Start a new Pokemon FireRed game on your Game Boy Advance and select your Johto starter Pokemon.