The Data files are excel data files, if you have excel just double click on one of them. They are in your Rocksim9/data folder. If your system asks what to open it with use excel. With a Mac I'm not sure if Microsoft has a mac version of excel. After thinking about the copy and paste process, if you have only a few custom files it would probably be easier to write the info down and add it manually. Because if you are not familiar with renaming files it gets confusing. With excel you can't open two files with the same name at the same time.