To install the Oculus Quest EZplugin file in ARC, follow these steps:

1. Download the Oculus Quest EZplugin file.
2. Open ARC.
3. Click on the "Project" tab in the top menu.
4. Select "Add Robot Skill".
5. In the new window, click on "Import".
6. Navigate to the location where you saved the Oculus Quest EZplugin file.
7. Select the file and click "Open".

The Oculus Quest EZplugin should now be installed in your ARC project. Remember, you can find more detailed instructions and support articles in the support section of the Synthiam website.