I was trying to put a new license plate holder on the trunk. All the (4) bolts on the rear license plate holder are rusted. I was able to get 3 of them out but one of it is so rusted that it does not come out. Its the lower right side screw that hold the license plate. I tried WD40 but still no luck. I have also stripped the Philips head screw a bit. Any thoughts on how to take it out?