Hello,
Lets go step by step:
1. Open xstore/js/etheme.js file and find 1983 line:
$this.find('>li').first().find('> .open-this').removeClass( 'fa-angle-down' ).addClass('fa-angle-down').parent().addClass('opened').find('> ul.children').show();
you may delete this line or simply add //
as on screenshots http://prntscr.com/gqb9wv > http://prntscr.com/gqba1b.
2. Copy full content of etheme.js file and add the code in this area http://prntscr.com/gqbbml on https://jscompress.com/ site, click Compress JavaScript button.
3. Copy result http://prntscr.com/gqbccf
4. Open etheme.min.js file, delete old content and add this code http://prntscr.com/gqbccf.
5. Save changes in etheme.min.js file.
Regards