Login to your wordpress dashboard and navigate to Plugins -> Add new
The click on Upload Plugin.
Upload the plugin you downloaded
After the Upload is done, click on Activate
Installation via FTP/CPANEL.
Navigate to your wordpress directory
The navigate to wp-content -> Plugins
Upload the plugin you downloaded and extract it
Then navigate to plugin on your wordpress dashboard find Areaexpress and Activate
Change Order Status to Ship via Areaexpress