How to change Apple ID password?

I don't really understand what you are trying to accomplish. Please clarify. But, assuming you want to change a password, see:

Change your Apple ID password https://support.apple.com/en-us/HT201355. And, see what Eric Root says above about what do after changing your password.

If you have changed your ID or password, have you followed the steps in this article?

What to do after you change your Apple ID or password - Apple Support.