JSFiddle - React, Tailwind, and code Playground

HTML

<h2 class="title" style="font-color: red;">Blog Post</h2>

JavaScript

var h2 = document.querySelector("h2.title");
var s = h2.outerHTML;
s = s.replace("<h2 class=\"title\" style=\"font-color: red;\">","<p>");
s = s.replace(/<\/h2>/g, "</p>");
h2.outerHTML = s;