Go to the process builder (to create or edit a process)
Go to the step you wish to add the video to and open the Basics tab
Scroll to the bottom of the Basics tab to find the Iframe/video feature text field
1. Load Youtube video in browser with the video you want
2. Control right click on the YouTube video
3. Copy the embed link
4. Paste the embed link into the text field and save the step
Start a test run and you will see the video embedded in the step.
This is what a video looks like in a run, perfect for training processes:
Soon you will be able to put in any standard URL for Vimeo and Youtube, without an embed code.