I'm trying to get speaker wire into my rear door. I have a 2000 chevy silverado ext cab truck. To get to the rubber flex tube that protects the wires going from the truck into the door, I assume I have to take off a piece of trim that covers it. I took the two big bolts that hold the seat belt in place by the rear door. I then tried to pry off the plastic trim that cases the seat belt mechanism. The trim won't come off, and I don't know how to get it off. There doesn't seem to be any resources on the internet as to how it comes off... any help would be appreciated Thanks in advance.