How do you change the form of rotom in Pokemon daimon?

On platinum, you need a mystery gift which is over, then you go to team galactics hideout and in the 1st room is a wall with a yellow and black checkered pattern. With rotom in your party, press A...

First, you need an action replay. Then get Arceus. Put him and a ditto in a day care. Turn off your game for three hours, turn it back on. Beat the elite four six times, take ditto out of the day...

You can't unless you trade it to platinum, heartgold, or soulsilver. or pokeshift to black or white.

To change rotoms form in Pokemon diamond go to the galactic HQ in Eterna city. When you're inside go to the right and you'll find a locked door.To open the door use the key you get from the mystery...

The basement in shopping mall nine, it has equipment and it changes rotom