2005 Mazda 6 headlights?

Disconnect the battery terminals, remove the fuse box cover and unbolt the square coolant tank on the passenger side of the car and move it off to the side.

For the driver side headlight, turn the wheel to the passenger side and remove or just drop inner fender liner. About a dozen little plastic rivets and 2 metal screws holding on mudguard. You really don't have to unscrew the screws holding the fender liner to the bottom of the front bumper you can just pull it down to access the back of the headlight.

DO NOT disconnect any of the hoses on the coolant tank or try to remove it from the car, just put it to the side.

Now you've got room to get your hands into where they need to go. You'll notice that there is a circular plastic cover on the housing behind the low beams. These each will unscrew and pop off. Once you take these off it is a simple matter of removing and replacing the bulb.

The bulb is held in by a metal latch. It is a wire that looks like a loop off a paper clip. disconnect by just push down and inwards (toward the middle of the car) on it and it'll pop up. Pivot it up out of the way and the bulb will pull right out. (actually, they both push towards the left if you are standing in front of the car looking at the headlights)

Replace the bulb and make sure you note how the old bulb was installed as it will only go back in one way. ALSO make sure you do not touch the bulb itself as the oil from your skin will cause the bulb to have hot spots and burn out sooner.

Reverse the process for the install making sure you get the metal tabs to latch in properly and make sure you secure the circular covers back onto the headlight housing. Also make sure you securely reattach the coolant tank and put the fuse box cover back on.

wd-40 on finger - finger to O ring - don't touch bulb glass