Windows 10: how to change online MS account to a local without new installation

[GB-UK]

Relatives have installed Windows 10 Home - with all MS online accounts.
How can one change to local accounts and delete the MS online accounts WITHOUT having to re-install this Windows?

[2x3i5x]

To switch your computer to a local account:

1. Open Settings > Accounts and click Your info.
2. After confirming that the account is set up to use a Microsoft account, click Sign in with a local account instead.
3. Enter the password for your Microsoft account to confirm that you're authorized to make the change, and then click Next.
4. On the Switch To A Local Account page, enter your new local user name and password, along with a password hint, as shown here.
5. Click Next to sign out from the Microsoft account and sign back in using your new local account.

SOURCE: https://www.zdnet.com/article/windows-10-tip-switch-back-to-a-local-account-from-a-microsoft-account/