I'm sorry to say that unless you know some pro hacking skills it's impossible.
There are 2 ways of playing as him. Action Replay or without Action Replay.
You can't
you cant...unless you have a action replay...though i dont really know if you can get mr.resseti on super smash bros melee without action replay sorry
What are the characters you get in Super smash bros brawl after using action replay
buying an action replay
NO, unless you are a good programmer/hacker.
If You Buy A Gamcube action replay it should have it. They can be found at gamestop.
go to a game store or walmart and buy an action replay for 20%
Find and use Action Replay
Using a gameshark/action replay
Action Replay.
No, there might be an action replay thing though... I know you can use action replay with Melee.