If you right-click on the .rar file, there should be a 7-zip option, and you can use that to extract the files. If you don't have 7-zip installed you should be able to search for a free version on Google to help extract them. After that if you double-click on the Strobovski program inside the folder it should ask you to download Unreal Engine to run it if you don't already have it installed. And then you're good to go.