The link to download Mnova is given below. There are versions for Mac, PC, and Linux. Download the latest version.
You will also need to download the four license files that are linked below. Right-click on each link, then select Save Link As...
It would be best to create a new directory for the license (.lic) file, but you may save the .lic files in your Downloads directory.
Begin by installing MNova. When the installation is complete, start MNova and install all four licenses.