You can unzip the Theme zip file on your computer and upload it to your website using FTP. Turn AutoRestore Off before uploading the Theme folder to you website. After uploading the Theme folder go to AutoRestore and click the wp-content Backup Files button and turn AutoRestore back On.
Or if you would like to add a php.ini file for your website and be able to change/increase the upload_max_filesize directive then see this Forum Topic link on how to add a php.ini file for your website.
http://forum.ait-pro.com/forums/topic/custom-php-ini-file-setup-php5-3-x/
PHP.net php.ini description for the upload_max_filesize directive
http://www.php.net/manual/en/ini.core.php#ini.upload-max-filesize