MaxxFitness theme provides easy management of social icons.
The list of icons is located at the bottom of the page
To edit a links go to maxx-fitness->Setting->Social links
To remove the icon just delete the link.
Edit or add network
If you want other or additional social networks, go to Appearance-> Widgets and add a text widget to Social position.
Sample code for the text widget:
Where Facebook, Twitter... - names of a social network;
https://www.facebook.com/ - link to the network.