Check out this post. If that is what your looking for tag @stephen_nutt for the code. I'm sure he's happy to share.
If you looking to just remove the icon you can use this in CSS (change tile # as needed)
#tile-1 .material-icons{display:none}
EDIT: To remove it all
#tile-1 .material-icons, #tile-1 .tile-title, #tile-1 .tile-primary {display:none}
