How to embed a collaborative document on Google (or other) Sites

Here’s a link to the G+ post with instructions: https://plus.google.com/u/0/115174107767353780511/posts/3px2V6AdcjC

…or you can the following link to view them directly (once the image loads, click on it to zoom in and scroll around): https://dl.dropboxusercontent.com/u/197021/Tech%20Posts/EmbedProcesScreenshot.png