If one of your students is stuck on a Pro Training task in a Challenge Course, a teacher can easily skip the task via the Teacher Dashboard.

Simply visit the Progress Reports page, and find the student from the appropriate class.

When you hover over the Pro Training challenge, you'll see an option to skip the task:

Note: Once a teacher has skipped the challenge in the dashboard, it's important that the student backs out of the challenge course in the app and re-enters to activate the skipped challenge.