Have a look on the guides section, theres a bit there about changing bulbs through the arches, but don't do that unless you have skin made from leather.
Just take your time, jack the car up and put it on stands. If its your first time, i would recommend taking both front wheels off to gain access.
There are 4 bolts under the bonnet, near the grill. 4 that attach it to the wings, 2 either side plus whatever else you have such as wheel arch liners.
Note, after years of taking them on and off, bolts inevitably get lost, broken and seized, so you might not have all the bolts there.
Its not the end of the world, just make sure its secure once you've finished with your headlight.
The headlight is held on by the bolts that are obvious when you remove the bumper. Unplug and remove!