FusedPress is designed to work with WordPress 4.0+, but it should work with older versions as well.
After you’ve downloaded the archive ( .zip ) file, you will need to extract it on your local computer. This will create a folder with the contents of the plugin. Using a FTP client ( FileZilla for example ), you will need to upload that folder on your server, in the wp-content/plugins folder.
Via WordPress Dashboard
In the WordPress Dashboard menu, hover over the Plugins menu item and click on “Add New”. Click on the “Upload Plugin” button near the page title. A new page will open with a box where you can upload the downloaded ( .zip ) file. Click the “Install Now” button.
Activating the plugin
If you have uploaded the plugin through the WordPress Dashboard, a new page will load where you will have an option to activate the plugin. If you have uploaded via FTP you can simply navigate to the Plugins page, search for the plugin in the list and click the “Activate” link.