Introduction
You can use SVN Repo Installer to download and install the plugins and scripts available here.
Installation
Download the latest version of SVN Repo Installer (includes xbmc4xbox-addons repository):
http://xbmc-addons.googlecode.com/svn/packages/plugins/programs/SVN_Repo_Installer.zip
Extract contents on your PC and upload through FTP into Q:\plugins\programs
Run SVN Repo Installer (program plugin) and you will see a new xbmc4xbox-addons entry, through which you can install the plugins available here.