[joeroberts]

you only need to
#1 go to admin panel set default them to what you want to use
#2 delete all themes but the one you want to use
#3 remove theme changer in theme/main.php
in this theme it is

<?php        echo "<p align=\"center\"><b>Theme</b></p>\n";
        echo "<form id=\"acp_styles\" type=\"hidden\" method=\"post\" action=\"#\">";
        echo "<p><select id=\"template_file\" name=\"theme_change\" onchange=\"if (this.options[this.selectedIndex].value != '') this.form.submit();\">".themechange()."</select></p>";
        echo "<p align=\"center\"><b>Language</b></p>\n";
        echo "<p><select id=\"language_file\" name=\"language_change\" onchange=\"if (this.options[this.selectedIndex].value != '') this.form.submit();\">".languagechange()."</select></p>";
        echo " <input class=\"button2\" type=\"submit\" value=\"SELECT\" /></form>";?>