Yes they can be romoved. Just get a razor or a knife, and with out scratching the frame pry them up. Also the replacement icons for the oil rigs are on EBay, the only downfall is they aren’t authentic. However they still fit like they should.
Read somewhere, if you put the frame under hot water for a brief while, it should loosen the glue which the Icons are held on by, then just pry gently but firmly.