Some good advice, if I may add a point or two - *If you start to strip a phillips head screw, or come across one that is already damaged, with the metal "pushed" out towards you, stop. Take an extension bar from your socket set and a hammer, place the flat end of the bar against the damaged screw head and give the other end some decent taps with the hammer to flatten the head out. Now tap in the screw driver or impact driver - you should now have a snug fit and the impacts may have loosened the screw a little. DO NOT re use the screw. *A small chisel can be used on screws with stripped heads. Place one corner against the edge of the screw head, pointing directly towards the center of the screw. few careful taps with a hammer to bed it in a mm or two, then tilt the chisel a few degrees so that the screw will spin counter clockwise and a few more decent taps. With both of the above make sure you can swing a hammer and hit the spot you want, keep a very good grip on the chisel or bar, and make your hammer blows strong enough to have effect or you are wasting your energy or time - and don't make the blows too strong, you don't a bar or chisel slipping. Another trick - for fasteners that are in good condition but stuck, push your body weight straight down into / on top of the screw and then turn the driver, hard, keeping the pressure on. Be careful not to push your bike over when doing this :o WD40 and coming back the next day can help as well.
