Unable to remove item from dock in Yosemite Apple says to remove an item from the dock in Yosemite, drag it from the dock until you see a puff of smoke.  I drag it from the dock, it has a tag called "remove" but it never goes up in smoke.It just returns to the dock.
Even though the items appeared not to be open, they were open.  By holding down the right click on the icon, a drop down menu appeared with the option to "quit." Select that item, and the icon is removed.