Answer by trante for Bootstrap 3 collapse change chevron icon on click

Similar to Bojan's answer, I use this solution.
Change HTML code like this:

<span class="chevron_toggleable glyphicon glyphicon-chevron-down"></span>

It's better to use .on event with respect to .click. Also by using class selector it can be used as a site wide solution.

$('.chevron_toggleable').on('click', function() {    $(this).toggleClass('glyphicon-chevron-down glyphicon-chevron-up');});