You install it by overwriting your files with the ones you'll receive in the download, then activating it in the siteadmin.
You'll get a new folder to upload to your themes directory, as well as a few files in some other folders, and these root files:
blogs.php
emailcompose.php
flvplayer.swf
some_skin.swf
index.php
memberprofile.php
memberprofile_ajax.php
page.php
play.php
recommendations.php
If you need to know about any specific files, just post back.
