What you need:
Selection of screwdrivers
Wire cutters
Soldering iron (if you want to do it properly)
electrical tape
Time about an hr give or take
OK, lets go...
1. open your boot (it gets trickier)
2. Remove handle on tailgate
3. Remove the trim from the highest part of the boot by giving it a firm tug to remove the metal clips holding it on (ignore the blue circles in this picture)
4. Remove the 2 little pop studs highlighted
5.Remove parcel shelf strings and then give the little clips a 90 degree twist and then you can pull them out
6. The panels are further held in place by two metal clips, circled, give the panel a firm pull to pop them off
7. repeat for the other side
8. Now you can remove the final part of the trim on the lowest part of the tailgate by pulling, start from the edges working towards the middle, there's quite a few clips.
9. Remove the plastic screw caps from either side
10. take the screws out
11, the middle screw is located through one of the holes under the lock, undo this too
12. You need to locate the wires going into the spoiler and give them a snip, its useful if you mark the wires as you snip so u know which ones go together when you come to refitting (unless you don't have a 3rd brake light)
13. Your spoiler is now free to come off, it probably will take a little persuasion as they have foam pads on their legs
14. well done, you've taken a spoiler off, it should look like this
As you can see it was rather vile under the spoiler so i took the opportunity to give it a little wash,clay bar,scratch x, paint clean and tech wax x2 but that's up to you...
Before:
After:
Not a massive improvement, but an improvement...
I took this opportunity to play about and see how lucky could look
Spoilerless:
Big wing:
This is for sale by the way if anyone wants it...
But i decided to plod on with the standard spoiler.
15. if your replacement spoiler doesn't have a 3rd brake light you'll have to remove this from the old spoiler by popping off the 2 red covers with a tiny screwdriver
then take out the screws and pull the light out with the cable, i took this opportunity to give the light a good wash and glass polish
16. Remove the blanking plate from your new spoiler and feed the wire through then fit the 3rd brake light
17. Take new spoiler over to the car, a friend is useful here to hold boot half open, feed the wire through the larger hole in the center (the one closest to you [unless for some stupid reason your standing on the roof])
18. start by holding the spoiler still and doing one screw on a side, just until the thread starts to bite,work from side to side, until all 4 are in to ensure it lines up right, then do the center and go back and tighten all screws.
19. Replace caps on outer 4 screws.
20. wire the spoiler back up, ensure to use electric tape to insulate the two separate wires once your done. Now's a good time to test your light works before you start to put all the trim back on!
21. Now you can start to put the trim back on, start with he larger lower part, clip the bottom in first then you need to push the top down towards the bottom then give it a whack to clip it in, you'll have to give it a whack in a few different spots to make sure its clicked on fully
22. side trim can be refitted, locate the clips into the holes and give a whack
23. put your parcel shelf clips back in and give a 90 degree twist, attach parcel shelf strings
24. pop the little pop studs back in
25, line up the final piece of trim and give a nice whack in the following places
26. attach handle back on
27. DONE!
Sweet guide mate 
SNAP 
