Instructions
Insert your "Pokemon Diamond" game cartridge into your Nintendo DS console and start the game. While you are in the game, walk to the closest town and enter the Pokemon Center.
Walk over to the PC in the far right corner of the Pokemon Center and select "Someone's PC" from the main menu. This will bring up the Pokemon Storage System.
Select the "Deposit Pokemon" option and place the bad egg from your Pokemon party into the folder labeled "Deposit Box 1."
Save the game by pressing the "Start" menu on your Nintendo DS device and selecting the "Save Game" option from the menu.
Remove the "Pokemon Diamond" cartridge and insert the Action Replay DS device into your Nintendo DS. Attach the "Pokemon Diamond" cartridge to the Action Replay DS and power on your Nintendo DS.
Press the "Star" symbol at the bottom of the Action Replay main menu. On the next screen, select the "Add New Code" option located at the top of the menu.
Enter the following code into the text field:
923FFFA8 00002400
B21C4D28 00000000
B0000004 00000000
0000C370 00000000
0000C374 00000000
1000C378 00000000
Press the "Start" button on your Nintendo DS console to launch "Pokemon Diamond."
Go into "Someone's PC" again and into "Deposit Box 1." If you have entered the cheat code correctly, the bad egg will have been deleted from the Pokemon Storage System.