JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wpq2">
    <div class="subClass"> 
        <a id="linkTO" class="subClass">New Item</a>
        or 
        <a class="subClass">edit</a>
        this list
    </div>
</div>

JavaScript

var parentID = document.getElementById('wpq2');
//get the first inner DIV which contains all the a elements
var innerDiv = parentID.getElementsByClassName('subClass')[0];
//get the HTML for the a element to keep
var a = innerDiv.getElementsByClassName('subClass')[0].outerHTML;

//replace the HTML contents of the inner DIV with the element to keep
innerDiv.innerHTML = a;