Hi

You have two options to get any addon installed.

1. Preferred method - Connect your site to the community with the account you have purchased the addon with and go to Dashboard and at the very bottom you will see a link to Extend Concrete5 and that will take you to a page that will let you install the addon.

2. You can download the addon from the Concrete5 site in Your Account - Licences section which will give you a zip file of the addon. Extract the files then connect via ftp to you site root and look for a folder called Packages, upload your files to that folder and then go back to your Dashboard and repeat the steps above to install the addon.

Hope that helps.