How can I programatically replace the text node within a NodeList?

Question

I have the following HTML structure:

<div id="container">
  <b>Hello</b>
  World
</div>

and I'd like to replace World with Earth like this:

<div id="container">
  <b>Hello</b>
  Earth
</div>

I don't want to modify the <b>Hello</b> element at all.

I can grab the container like this:

var el = document.querySelector("#container")

which has three element in childNodes, the last of which is a textNode:

Is there a way to replace the text in the last element without modifying the entire innerHTML or innerText?

var el = document.querySelector("#container")

console.log(el.childNodes)

<div id="container">
  <b>Hello</b>
  World
</div>