Use a free tool like 7-Zip (Windows) or The Unarchiver (Mac).
Right-click the .rar file and select "Extract Here" or "Extract to [Folder Name]." Download Gotthard Heaven (Best Ballads) 2010 rar
If you have already acquired a legal backup in .rar format, you will need a utility to extract the music files: Use a free tool like 7-Zip (Windows) or The Unarchiver (Mac)