The scripts provided create the CMS virtual machine image based on CernVM, with Scientific Linux CERN 6 (slc6).
First, you need to run a normal Micro-CernVM, using your own context so you can login. Copy the attached files to the running VM and then login.
Inside the VM, you first need a copy of the latest Micro-CernVM release as a template for the Open Data image. Download it, inside the running VM, from: https://cernvm.cern.ch/releases/ucernvm-images.2020.07-1.cernvm.x86_64/ucernvm-v4prod.2020.07-1.cernvm.x86_64.hdd placing it in the same directory as the other files.
Run the script:./cernvm-script
which will produce some output on the terminal, and then finish.
The result should be a file with the title coming from the -n field in the script. In this case, the file we're interested in is: CMS-OpenData-1.5.3.ova
which can be copied from the running VM to elsewhere.
The open data are released under the Creative Commons CC0 waiver. Neither the experiment(s) ( CMS ) nor CERN endorse any works, scientific or otherwise, produced using these data. All releases will have a unique DOI that you are requested to cite in any applications or publications.