EASY. GET ROCK SMASH!
You don't.
easy just win a Pokemon contest
You can use Feint (if you have diamond/pearl/platinum, monferno learns it).
You must obtain the National Pokedex. (And it's PAL Park, not Pearl Park.)
Defeat Team Galactic on Mt. Coronet.
HM06 Rock Smash is given to you by a Hiker in Mt. Coronet.
cach pearl the legndary Pokemon
past floroma.
you have to have action replay
i smell bad
You have to beat the league.
YOU WILL NEED TO GET A STARTER POKEMON ok.
Turn left at the bridge, straight on past the Pokemon Centre, right past the Pokemon Mart, through the temple of flag, then there you are!
You need action replay to do this cheat but it is only on Pokemon pearl
Beat the GYM LEADER [=
Complete sinnoh dex
Go through the cave