I searched the forums and could find only windows/regular PC keyboard based icon removal keys (http://ubuntuforums.org/showthread.php?t=1965518) so I just wanted to make this for mac users that will need help down the road.
To remove icons from the taskbar after being placed onto it, Hold down the apple key/super key + alt then while holding down the keys right click on the icon and it will give you the option of removing or moving it. To right click (for me) is a 2 finger tap on the touchpad (for laptops) may be 3 fingers for some so try different approaches to see what works.
Hope this helps!
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