Once you have downloaded the latest package you need to install your plugin following the steps below. Lets assume you want to install a plugin named "NewPlugin", and the name of the .dll file in the download is "Nop.Plugin.AType.NewPlugin.dll"
1. Unzip the contents of the download to a new empty folder on your computer.
2. Go to the Plugins folder of your nopCommerce installation and create a new folder named AType.NewPlugin.
3. Copy the contents of the unzipped download and paste it all in the AType.NewPlugin folder.
4. Login to your web site as an administrator and go to Configuration, Plugins.
6 . Click on the "Reload List of Plugins" button in the upper right corner.
7. After the screen refreshes, scroll down and find the new plugin in the list and click on the "Install" link.
8. After the screen refreshes, the plugin is installed, but you may need to configure it before it can be used. Use the "Configure" link to setup any specifics required for the plugin. You'll find instructions for each plugin on its own configuration page.