Instructions
Start "Pokemon HeartGold" on your Nintendo DS and wait until you see the Ho-Oh bird Pokemon flying on the lower screen of the system.
Press and hold "up" on the control pad, select and hold "B" until the game asks if you want to delete your saved file. Confirm your choice to delete the previous save file. Do not turn off the power until the save file has been deleted.
Start a new game file when the system restarts, and type in your Pokemon Trainer's name when Professor Oak asks. Save the game to confirm your new name for the next time you play "Pokemon HeartGold."