One option is to replace one of the existing social icons with that of the Instagram icon. You will find the icon images located in the ../templates/j51_polaris/images/social_icons folder from the root of your Joomla installation.

Ciarán

now that I changed the social icon, how do I change the name when you hover over it?

I made the vimeo icon instagram, so how do I change the word vimeo?

Hello

In your templates header.php (../templates/j51_polaris/php/layouts/header.php) locate the following (LINE 41)...

<li class="social-vimeo"><a href="/<?php echo $this->params->get('social_vimeo'); ?>" target="_blank" title="Vimeo"></a></li>

And replace with...

<li class="social-vimeo"><a href="/<?php echo $this->params->get('social_vimeo'); ?>" target="_blank" title="Instagram"></a></li>

Ciarán