Hi, with huge difficulty and scuffed knuckles, the drivers side is the easier of the two.
1) remove the engine cover by twisting the knobs half a turn.
2) depending on the bulb (head light or fog light) remove the circular rubber cap and do your self a favor and stand to the side of the car looking towards the back of the light cluster.
3) looking at the light cluster you should see a black plug shaped like a letter "n" with a single wire connected, holding the block NOT the wire pull firmly towards you to remove.
4) now looking at the back of the bulb you will see a wire spring that clamps down each side of the bulb terminals it will have an end that has a round piece, holding each one between finger and thumb squeeze together and swing open like a door.
5) the bulb should now be free so replace making sure it goes in the correct way (three prongs like a triangle with the bottom two closer together)
6) now reversing the steps swing close the spring clamping the bulb, connect the "n" shaped plug to the bulb and test and put back the rubber cap and engine cover.
Now for the passengers side, what clown put the ABS unit behind the light cluster and in that tiny amount of space you did have to do the drivers side bulb?
1) turn off the engine and remove your key, just in case you are in any doubt turn off everything.
2) on top of the ABS unit are the wires and the connector plug and to the side is a red clip, using a screw driver leaver out the red sliding plug and this will allow you to move the plug out of the way and give you that few extra inches to work in.
3) then the same as the above for the drivers side.
NOTE be VERY careful when removing the connector plug do not force put much effort into removing or re-connecting the plug the pins can bend real easy.
Good luck and have fun!!
Alexander Swift
2003 Xsara HDI Coupe
Alexander Swift
December 2007