1. You need to have a ftp server setup on your oxwall server...Then in the admin panel of oxwall on the left side of the screen go down to plugin and then select add new. Choose the plugin fiole that you just downloaded and then click Upload then you will be asked for your FTP username and password then it will load the plugin in for you...Then go to Available Plugins there you will see the plugin and then just click on the install.

2. Is to take the zip file you downloaded and unzip it once you have done that you will see a folder that starts with the name of the plugin (example: comments) now take that folder and copy it to the folder ow_plugins then when that is done go into you site and then the admin panel and check if it is there in the available plugins or installed plugins.