Hello mate and WELCOME TO THE FORUM!
If you mean the headlight itself, then----
There are 3 10mm bolts holding the headlight on. Undo them....(2 at the top of the headlight and 1 on the side)
You will need to remove the bumper, or move it forwards slightly to get the headlight out. I normally do this by removing the 2 bolts either end of the bumper (under the wing) and then the two bolts in the middle of the bumper (at the top that you see when you open the bonnet). This will allow you to move the bumper forwards enough to remove the headlight. Then unplug the electrical plugs at the back, and your done.
Hope that helps,
Alan