I have an xml document that resembles the following:

<?xml version='1.0' encoding='UTF-8'?>
        <document xmlns='https://www.example.com' xmlns:asi='http://www.w3.org/1999/xhtml'>
            <articleID>1234567890</articleID>
            <article>
                <title>Some random title</title>
            </article>
        </document>

Using lxml, I want to be able to override/replace the root element's namespace/nsmap so that it resembles the following:

<?xml version='1.0' encoding='UTF-8'?>
        <document xmlns='https://www.somethingelse.com' xmlns:asi='http://www.w3.org/1999/xhtml'>
            <articleID>1234567890</articleID>
            <article>
                <title>Some random title</title>
            </article>
        </document>

How could I accomplish that using lxml?