Hello,
Yes you can definitely do that but it will require you to edit the theme files.
Edit the our_team_widget.php file located in the /inc/widgets/ folder.
On line 75 change the fa-instagram to fa-imdb
See here https://www.dropbox.com/s/973px6vwn93okcy/imdb-team.PNG?dl=0
You will see I circled it in red in the screenshot.
Let me know if you have any trouble.
