We've gotten ourselves a 5-year-old Toyota Highlander V6. The first oil change after we got the car I had to hire out because I couldn't get the filter cartridge to break free. Now that that's under control and not torqued to 300 foot-pounds, I have another small issue. I noticed as I did the last oil change at home the drain plug washer is frozen or stuck HARD to the oil pan. I couldn't remove it to replace with a fresh blue Toyota OEM washer (I keep a pack of those on hand), so I just reinstalled the plug. No problems, no oil leaks. But still, I'd like to use a fresh washer next time. How do I remove a seized washer without damaging any part of the oil pan?