you cant
it doesn't in Pokemon dimond but i don't have Pokemon platinum
any box and press delete
you do new game then save over the other game
To delete your account on Pokemon Platinum you need to press B and Up while you are on the main menu at the intro of the game.
the move deleter in canalave city :) =)
Up+SELECT+B all together
The house above the pokeshope in canalav city
delete the game and then u finished
What you do is hold all three button combinations for at least 3 seconds and confirm delete.
i have had no experiences with it and i do it a lot on platinum
pres up star and select at the top menu
delete your game and start a new game with the name galax