Unset/Forget/Repalce a user git Credential.Helper and remember new one

The easiest way to delete credentials for Git is to run a command like the following, which tells whatever credential helper you're using that the password is invalid and it should delete it:

$ echo url=https://bk2204@github.com | git credential reject

Your URL must have the proper scheme, username, and host, but generally need not have the remainder of the URL (unless you've set credential.useHTTPpath) or the password. This should work anywhere the credential helper speaks the protocol correctly, although it is known that the Git Credential Manager for Windows is broken in this regard.

Once you delete the existing username and password, you'll be prompted again the next time and can enter a new username and password. Note that if you need to have two different usernames for the same domain, the easiest way to do that is to put the username in the remote URL, and the credential manager will automatically fill in the right password for the right user.