Manage Apple ID : transfer data

I bought my son , who is 7 years old, an iPad  2 years ago. He  is using my Apple ID  on his iPAD. I would like to transfer the Game Center and all the game levels with different Apps ( e.g. Minecraft, Roblox) that he has accumulated, to his own Apple ID. Once I've created his own Apple ID , how can I transfer all the Game Center data to his new account and remove it from my Apple ID account.

Can you guide me through this.