I have a Westy with the original Blaupunkt speakers that desperately need replacing. I would like to reuse the original Blaupunkt speaker grills so here is my question.. How do you remove the speaker grills without damaging them?? Do they pry off or is there some secret to removing them..?? The two in the doors have metal covers and the two in the A/C cabinet seem to be made of plastic..Any suggestions??