The 7Zip archives can be extracted with almost any archiver released. Typically, the recommended way is by using the 7Zip application available for downloading through the application's page at Software Informer. However, you can use WinRAR as well, but the 7Zip is open-source and it can be used for as long as you want.
Visit the application's page to download it, then install it and right click the archive and extract the contents of the 7Z archive: http://7-zip.software.informer.com/