Editing XML File
Open templateDetails.xml, find this line
replace it with the following one
Go toTemplate Manager, Select the template, inside Template Configurationpage's Layouttab find Responsive Layoutoption and disable this.
Editing PHP File
Open index.php, go to the bottom of the file, search for the following lines and delete or comment <?php / Begin Off-canvas / if($expose->countModules('offcanvas')): ?>
<?php /** End Offcanvas **/ endif;?>
Editing Less File
Open responsive.less, comment all lines except the following one @import "../../../libraries/expose/interface/less/responsive-utilities.less";
Finally delete the cache and full refresh your browser.