JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <p>Before</p>
    <p id="damn" style="color: #355e95"> <i>Hello</i> </p>
    <p>After</p>
</body>

JavaScript

function changeTagName(el, newTagName) {
    var n = document.createElement(newTagName);
    var attr = el.attributes;
    for (var i = 0, len = attr.length; i < len; ++i) {
        n.setAttribute(attr[i].name, attr[i].value);
    }
    n.innerHTML = el.innerHTML;
    el.parentNode.replaceChild(n, el);
}

changeTagName(document.getElementById('damn'), 'h1');