How to install a Theme
Click on the Select a Theme Button
You are probably use to installing themes under the WordPress theme menu, but in the case of themes for the SeedProd Coming Soon Pro plugin you'll install themes under the plugins menu.
Just goto Plugins > Add New and click the Upload Plugin button and select the theme zip file.
Next activate the plugin.
After activating goto the Coming Soon Pro plugin menu and click the Design Tab, there you should see the theme screenshot like in the image below.
Next click on the screenshot to load the theme and finally click Save Changes.
The theme should now be loaded. Note this will override any existing setting under the design tab so make sure to export your settings if you need to revert back.