blowing injector on 2.5 td movano?

my 02, 2.5 td vauxhall movano is blowing on injector 1, i took it to a garage and they couldnt remove it and told me to leave it as it should seal itself. it hasnt, it is now blowing quite badly and the hot gasses emitting from it have melted a rubber pipe(oil feed pipe???) in front of it. This has caused oil to blow out the hole and cover the engine in oil. nice. the tube is supposed to have a metal tube on the end, but i presume this is still in the top of the engine.
What i need to know is what the melted part is calle so i can replace it and any advice on removing the injector without damaging it. i am prepared to replace it but dont fancy taking the head off to remove pieces of injector.

cheers