The Altering Cave is a fixed location with a set layout, and there is no way to change it in the game. The only way to change the cave is to use a GameShark or other cheating device, which is not recommended as it can corrupt your save file.
If you're looking to explore different caves or locations, you can try playing other Pokemon games that have different environments.
However, you can change your experience in the Altering Cave by:
* Choosing different Pokemon: The types of Pokemon you bring with you will affect your strategies and success in battles.
* Using different items: Items like Repels, Potions, and Pokeballs can make a big difference in the Altering Cave.
* Exploring every nook and cranny: You can find hidden items and valuable trainers to battle in the Altering Cave.
So while you can't change the cave itself, you can change how you approach it and what you experience within it.