The file you have download this is the theme package zip file where include themename-pro.zip, xml file and sql file so when you finish the download just extract the theme package and you just need to upload themename-pro.zip file in the WordPress. If you still have problem please send us the login details we will upload the theme on your WordPress.
After theme installation you can find the options in Appearance >> Theme Options.
There is no need to change the class please send the site url and the login details to support@flythemes.net so we can check the backend and resolve the issue.