Originally Posted by Peter_Crowl;
Word of caution - if you try to remove a clutch drive screw with a bodged tool you'll render it damaged beyond removal by the correct tip. Use the right tip from the get go.
Been there, botched that! I guess you can always drill the head off, but the bit's going to wander into the aluminum if you go too deep. I've been there too. By the way the screws might come out a little easier if you soak the heads with some penetrating oil and let it sit for a couple days. It's hard to keep the oil in place but you can wet the head with a Q-tip and some of it will wick under, eventually.
I also found some vice grips pretty handy in getting the more stubborn screws out.