I want svn update to overwrite my local file with the files from the server, even if my local files have modifications, I want to throw them away and use the version that\'s on
You should use SVN revert. This would revert the files in your working copy to their original state. For more information and examples check the svn book here:
http://svnbook.red-bean.com/en/1.1/re25.html