Sounds nasty.
Had the same problem, some twit thought it would be a good idea to stick the side trimmings on with black silicone.
I bought a knife, the ones you can snap a small section off at a time. Pulled it right out, put a little insulating tape around the tip of the blade. Place a little pressure on it to form a bent and then slowly worked my way down it, getting it close and not to hit the paint. Then with a little petrol, work it in to the area affected only leave for 5-10 mins and pick away with your fingers. It would be a good idea to grow ALL your finger nails because you will need them.
