Let me throw in another bit of advice. With the long torx bit, rap on the screw head before atempting to turn it to help loosen it. Also, if you're flushing with fresh water, it's hard to get enough antifreeze back in if you pre-mix it. I fill with the right amount of pure antifreeze (50% of capacity---can't recall the exact amount, but it's about one bottle's worth), and than add water to make up any shortage in the system. You should recheck after driving to make up for any air bubbles that work out. Off to birdland.