Trying to run a wire to an aftermarket subwoofer and think I need to remove the rear seat side bolster to run the wire. I haven't been able to remove it. Would appreciate some suggestions. I saw that you are supposed to tug on it at the top (pulling towards the front of the car) and have tried that repeatedly. Quite firmly, too. I also saw the approach to use a metal tool to pry the top forward, and that didn't help. Is there a trick? Is there a hidden fastener or catch I have to release?