Duster inside window cat whisker replacement

I replaced mine last year. I attached the new ones with little screws, predrilling the plastic first. Getting the old ones off was a *****, until I fashioned a couple of little hooks out of coat hanger wire. I then used them to hook up under the u channel on either side of the little barbs that bite into the plastic. By working the hooks under the u channel, they spread the channel open enough to ease the u channel off of the plastic door top trim. Had to take my time and work along the full length from one end to the other, but it worked great where cutting, bending and mangling had failed.