The extension can be downloaded:
- Via MagentoConnect
- Via Github (for skilled developers and if you want the latest development version)
In each case, please follow the instructions provided in each channel as each channel has in its own way to do the installation.
The MagentoConnect channel is the easiest way to install for non-developer and the latest stable version will be found. However the latest development version and fixes may be in the Github channel first. As the Github channel is used to push all fixes and changes.