Hello and welcome to JustAnswer

the plastic fender liner need to be loosed and moved, or removed to gain access to the bolt, it holds the headlamp in place from underneath

are you trying to replace the driver or passenger side headlamp? it helps to turn the wheels to the full turn position depending on which headlamp you are trying to replace

the item labeled "3" is a nut that also needs to be removed and "1" is the electrical connector that needs to be removed.

if replacing the right headlamp turn the steering wheel to the left ( counter-clockwise) until lock.
if replacing the left headlamp turn the steering wheel to the right ( clockwise) until lock.

the screw is only accessible after removing the wheel well liner and will be accessed from the cavity created by removing the panel, if memory is correct the screw is a hex head, it might have a torx head on it though. make sure to turn the steering wheel all the way to the right (clockwise) to give yourself more room

no, one second I have a picture for you, i think you may have only removed part of the panel I want you to remove

sorry, i linked you the wrong image, one second please

after the little access panel on the right comes out, the larger trim piece that covers the wheel well needs to be removed, you can see the bolts that hold the panel that needs to be removed labeled as "4" in that diagram