Taking the headlight out is a fairly easy, albeit lengthy, process as several items need to be removed for access. First of all the front bumper needs to be off. Next remove the two splash guards in the wheel well (the wheel will need to be off the car as well):
Next you’ll need to remove the two bolts holding the rear bracket in place (circled in red);
Access to the front one is tricky and requires a long, thin socket extension:
Next you’ll need to remove the bolt holding the side of the headlight in place. This is accessed from behind a grommet in the front boot compartment (out of interest, the hex socket to the left of the bolt in the picture below is how the aim/level of the headlight is adjusted):
Finally, there are two bolts holding the front of the headlight to the radiator frame (the front bumper will need to be removed). I have shown a picture of their holes with the headlight removed in order to best show their location:
Undo all the electrical connections and the headlight will then carefully withdraw from the car (through the wheel well). If the car is fitted with OEM HID lights then the ballast units will need to be unbolted to give enough space.
If you want to split the headlight open I recommend you leave it in a warm place to soften the glue bonding the glass to the body of the light.