Step 1
Click on the Learning Experience Styling option located under the Design tab.
Step 2
In the upper right hand corner will be a Downgrade to V2 button:
Click this button
Step 3
A confirmation modal will appear to ensure that you do in fact want to proceed with the upgrade:
If you no longer need to do the reversion, click Cancel. If you'd still like to go back to V2, click the Downgrade button.
Step 4
Your Learning Experience will now be set to V2 for all learners within your instance:
When you are again ready to proceed with the upgrade, you can follow these instructions to complete the process.