To remove your files from your devices, first, go to the Content Manager section of your Dashboard. Here you will have an overview of all the files you have uploaded, at the bottom of each file you can click the checkbox to publish or unpublish your file. Deselect the checkbox to remove the file from your devices.
If you want the files to be removed from VR Sync permanently you can click the trash icon in the Content Manager.
Please note that the file will only be removed from your devices once they open the VR Sync application and connect to the internet again.