Ok figured it out myself. Have to pull the whole metal strip off the rubber entirely, all the way down to the wing mirror, being careful not to bend the metal any more. Then put it back on from the top right (in my case for the left hand front window), where the metal hooks in to the rubber. Then slowly bit by bit I pushed the metal back onto the rubber with the palms of my hands, starting from the top right and all the way down to the wing mirror. I’m not sure if it made any difference, but I was pushing up from the bottom edge of the metal first, then pushing the pressure up and over the top. Snapped back on fine, looks normal again. Hope this helps anyone in similar situation!