Font Awesome icons set (http://fortawesome.github.io/Font-Awesome/icons/#brand).
Here are the instructions to change the media icons to whatever icon there is on Font Awesome:
Step 1: Visit http://fortawesome.github.io/Font-Awesome/icons/
Step 2: Click on the wanted icon. Social Media icons are under "Brand Icons" close to the bottom of the page.
Step 3: Copy the tag in the rectangle, which starts with "fa-", e.g. fa-instagram, fa-google-plus, fa-linkedin.
Step 4: Go to WordPress Admin page > Clubix Options > Contact and Social Options
Step 5: Under Social Icons section, either:
a) replace existing icon containing "fa-anything" with the one desired, say "fa-instagram"; or
b)
click the Add More button and type the following, replacing the icon
and link parts accordingly: [clx_isocial icon="fa-whateveryoupicked"
href="#" /]
credits: Jonatas