To open the Elite Four, you have to get all the Gym badges.
No its not an HM in leafgreen.
The best team to beat elite 4 in Pokemon firered and leafgreen are the first six Pokemon you caught and trained
train your Pokemon that's it.
Beat the elite four.
After you defeat the Elite Four.
your strongest Pokemon
get some good pokemon with good move
Prof oak after beating the elite four.
You speed through the credits and re-open your game. Then you can continue to catch and train pokemon.
You have to beat the Elite Four once.
beat the elite four and your starter has to be a bulbasaur
all you have to do is not get beaten