Seeing the mould split lines on my key, I think you may find it difficult. I think the metal key blade is moulded into the plastic part. The first picture you posted shows that the base of the metal part has a lug on it. You could take a chance, hold it firmly in a vice and pull very hard on the blue plastic bit, but I reckon you'll wreck the plastic.
Where did you find the first picture? As that shows the metal bit on its own, they must have managed to get it apart!