You can't. either Turtwig, Piplup, or Chimchar. piplup is mine :D
Once you choose your gender at the beginning of the game you can't change it.
You cannot change your ID on any Pokemon game, let alone Pokemon Diamond. When you buy the game, the ID number is the number you get, you cannot change it.
You can get him at the beginning of the game by choosing it as your starter Pokemon. You can also trade it from someone who has the game also if they have it.
Lake variety, one of the choices at the beginning of the game
your question Doesn't make any sense , you can't change the 3 starter Pokemon. and what is "this a cheat" mean? use action replay to change starter Pokemon into what you want. you might need pokesav.
you cant see a chimchar in Pokemon diamond so you are saying that no trainer in the game has a chimchar
Change the DS time then save your game again on diamond the time in the game will change with the DS time.
Uh, start a new game and save at the beginning.
Play the game during the day.
Roserade. But it takes patience to train it from a Budew at the beginning of a game
You can' get Infernape, it's an exclusive starter you can choose at the beginning of the game.
Yes. Start the whole game from the beginning.