Disabling Local User
Follow the steps below to disable a local user:
Go to Settings > General > Users and Roles.
The Users and Roles page opens in the Users view. Hover over the local user you wish to be disabled, and then click the Ellipsis icon in the rightmost cell of the row.
In the resulting menu, click Disable.
In the dialog box that opens, click Disable again to disable the local user. The user will appear dimmed in the list of local users.