Before you take any steps please backup your site and database (just to be sure).
1) Install the CDN for Joomla! Extension:
- Download the CDN for Joomla! Extension from NoNumber.nl website. (You do not need to unzip this file)
- Log into your Joomla administration section
- Click on the Extensions tab in the top navigation bar and select Extensions Manager. You should be in the Install section, if not click on the Install link at the top
- Look for section titled Upload Package File, click on the Choose File button and browse to the CDN for Joomla! Extension you downloaded
- Click on the Upload & Install button to install the extension into your website.
2) Configuring the CDN for Joomla! Extension:
- Click on the Extensions tab on the top navigation bar and select Plugin Manager
- Search for the CDN for Joomla! plugin – you will find it under the name System – CDN for Joomla!, and click on it to edit the settings
- On the settings page under Basic options type in the CDN domain field your CNAME (only if you have configured it in Advanced configuration) or enter your CDN url. Both of these entries can be found under CDN List in CDN77 client section. Click on Save.
You are now using CDN!
View the page source of your website to verify that this is true. Details here.