It's a lot to accurately explain in a post. So i'll let you know what the vital points are. If you're mechanically minded it shouldn't be too difficult to then deduce what bolts need removing around that area.
- Remove Wheel, Bumper, and arch liner.
Points to remember (in no particular order).
1) There is a 10mm bolt underneath the triangle casing in the wing mirror area (not the actual wing mirror) it's the casing that doesn't open out with the door and fits in the corner section of the wing.
2) There is a 10mm bolt underneath the car next to the jack-point cover by a load of adhesive gunk - this will need removing. The Side-skirt will need to be removed or part removed/loosed to free the arch from this area, once said bolt has been removed.
3) With the bumper removed there will be a white bracket which will need to be transferred over to the new wing. Remove and retatin this.
4) All the bolts that require removing will look the same - IIRC, there is about 6-8 of them, and should be in the colour of the car. Mine were all NHB.
5) There is some window trim that runs up the side of the windscreen, this will need removing to get at another one of the bolts mentioned in point 4.
6) Unless you are removing the door (I didn't) there are some clips in the door area, where the hinge is, that will most certainly snap unless you remove them from the inside - this can be done via removing the arch liner and attacking them throught the wheel arch. Just pop these out as these will need to be popped back into the new arch via the door area again - this is fiddily. These pop clips are delicate.
7) Carefully open and close the door first time the arch has been fitted as you don't want them to foul each other and dent/damage one or the other due to mis-alignment. I have fitted aftermarket which had alignment issues. OEM arches went on a doddle, when I fitted them for someone else.
I'll see if I can find some pictures of the wings that I had removed, and the replacement wings that I had bought - as these will have bolt holes on them, which'll help to give you an idea of where you need to be looking to remove bolts from.
Here's one I found of the wing removed - that'll give some idea, until I can find other pics.
If you need any help give me a shout. It's best to work in sections - by this I mean undo everything in the area that you are working on - it's a lot more organised, and easier to keep a trace of what goes where. Once you've done one side, doing the other is a doddle.
One with new wing fitted