Change Twitter Link in Header

To the left of my dropdown menus I have 4 icons – mail, facebook, twitter, and youtube.
I am trying to change the destination of the twitter link.

When I go to “appearance – widgets”, I only have the option to change the icons that are in the footer, there is no option to change the header ones.

So I went into “appearance -> editor”, but I have no idea which theme it is held in. Any ideas or easier way to change it?

When I view the source code I see
`</a>
</div>
<div class=”social-icon”>
<a href=”https://twitter.com/ol_onechance&#8221; target=”_blank” >
<img width=”32″ height=”32″ src=”http://www.onelifeonechance.ca/wp-content/themes/charityhub-v1-02/images/light/social-icon/twitter.png&#8221; alt=”Twitter” />
</a>`

All i need to do is find where this code is stored, and change the text to my new destination, correct?

Thanks in advance for you help and patience.