You're using Ameritage Medical, but you posted to the board for Risen Hope; I was wondering why I had no idea where that screenshot came from. I'll move this thread to the correct board after I submit this post.
The CSS you're looking for is the following, around line 684 of css/template.css:
background: transparent url(../images/s5_phone.png) no-repeat left;
You can either change that code to point to a different image, or you can override it with the following code at the bottom of the style.css file for the theme (after changing the URL):
background: transparent url(../images/s5_phone.png) no-repeat left !important;