Some times I don't thing oiling those particular screws works - the oil doesn't have a good way to penetrate. I think strong arms and a ratchet screwdriver works. Too much heat can discolor the machine. The wrong screw drive can tear up the screws and still not have the plate off. I have a real long screw driver and some times it works. A long time ago a repair man gave me one he ground off at an angle. It sure worked nice. It was stolen one time when someone broke in. I'm sure they were disappointed but not as disappointed as I was.