After download the package, please proceed with the following steps:
Please unzipped the archive.
Installing the extension. You can check compilation state in System > Tool > Compilation, see "Compiler Status". If status is "Enable" to change it to "Disable".
Disable cache at System > Cache Management.
Unload the contents of the module package to the Magento root folder. This will not over write the existing Magento folders of files, only the new contents will added.
Refresh your admin user access rights: logout from your store admin and then login back. Next, please Enable Cache.