You can use ftp to upload your assets, then visit the Files & Images section in the CMS to let SilverStripe know about them.

Probably reason you have problems with chmod and upload is that your web server has created that folder (and is now a owner of files) so it is writable by your server not you, so if you really need this manual upload then try using some sort of chmod script like this bellow:

<?php
chmod('/FULL_PATH_TO_ASSETS_DIR', 777); // this should after upload be 755
// so after you finish comment line above and "restart" this page (refresh)
#chmod('/FULL_PATH_TO_ASSETS_DIR', 755); // later uncomment this line
?>

or much better read docs about chmod from php at http://www.php.net/chmod

when giving us the script you did, where would I run this. I did FTP multiple files to the Assets/Uploads folder but when I access the files&images section they do not show, how do I refresh this folder?

thanks