hi, thanks for downloading! :D
you need a WinRAR extractor, you can download it for free here, it’s only around 2MB so it won’t take that long to download. btw WinRAR is an EXTREMELY important program to have, it basically unzips all types of bundling/compiling file extensions (lol i sound like an ad but yeah, once you have it you need not worry about unpacking files ever)
once it’s installed, you just right-click the .rar file then choose ‘Extract Here’

hope this helps :)