After downloading the Plugin from codecanyon. Unzip the file and you will get a zip file with the plugin name.
Now visit the Plugin page from the Cmslooks admin dashboard. Here you can see all the available plugin list.
To add a new plugin click the Install Plugin Button.
Now you have to upload the plugin zip file. Then click install and wait for some time. After successfully installing you will see a new plugin is added to the list.
In the Page List you can see a new Plugin is added.
Now you have to activate the plugin to use it. Click Activate. If the plugin is licensed Give purchase key to activate.
After the plugin is activate, You can work with this.