It would work on an existing install, however you need to install the Wordpress Reset Plugin to guarantee the best performance of the theme.

* Please be aware that once you use this plugin, all your current database will be deleted. 

To install and use the Wordpress Reset plugin:

Step 1 - Login your admin dashboard >> Plugins >> Add New then search the keyword Wordpress reset >> Choose WordPress Reset >> Hit Install Now 

Step 2 -
 Go to Tools >> 

Step 3 - After set up theme, let's click to Activate

Step 4 - Navigate the mouse to Plugins >> Installed Plugins >> Activate >> Apply