It's long to explain but easy in theory man. Not hard but extremely fiddily and frustrating.
- for maximum space, you can remove the side-skirt - it's not mandatory though, but the front end of the side-skirt will need to be free.
- remove the wheel
- you'll need to remove part of the wing mirror housing, and windscreen trim, the arch liner, bumper. You do not have to remove the door. There are a couple of fiddily clips that would go in a whole lot easier without the door in the way though. These clips will likely snap, so I'd pick up replacements.
- expect a 10mm bolt under the car to be submerged in some pretty tough/sticky gloop; you'll need to work away at that to get at the bolt.
- I would only do this if you're comfortable fcking with cars, as you do have to strip a lot off (parts, clups, screws, bolts, trim,) the top to get at the main bolts that affix the wing.
- I'll see if I can pull you out a picture tomorrow that shows how that area of the car is put together, if you locate all of the parts you'll get an idea of how to take it apart. Personally, I'd remove the bumper first, and all the wing related clips/bolts/screws. Then I'd move in to the engine bay and free the wing via it's fixtures in the bay. After that I'd focus on the area around the door and wing mirror. Lastly the bolt and fixtures underneath the car.
Be careful when you remove the old wing, it can damage paintwork.
Also don't slam the door closed when you first fit and align the wing otherwise you risk catching the edge and fcking up the wing and/or the door.
If you need help, PM me and you can have my number and I'll talk you through - I've fitted at least 3 pairs so that's 6-wings on and off three times each etc.