The ariel its a bit tricky
start by opening the boot and rolling the black rubber trim of the side edges so that the plastics on both sides that the parcel shelf sits on can be pulled pulled free, they are held on with a few screws, undo these. The panels don't have to be totally removed but they do need to be free, they are held in by some lugs so do need a good tug.
The lighter coloured panels above where tyre alarm movement sensors are also need to be freed, again these are held by lugs so need a good tug. These panels need to be free to provide space for the roof panel to move.
Next up is to get in the back of the car and pull free the black panel that sits above the rear side window.
Back to the rear of the car. If you look at the roof lining you will notice 2 light coloured clips, these just pull our towards you. You should now be able to work the roof panel free, it takes a bit of jigging about but you can get enough space to get your hand and a ratchet wrench in, I think it was 15mm but can't be too sure, sorry.
once you have removed the nut holding the ariel on you can remove the ariel base from the top of the car. To fully remove the ariel you simply unplug the wire at the connector, if you can leave it loose so your wrapper can lift it that may be the better option. I fully removed mine as I fitted a shark fin.
One thing to note is that when moving the roof panel about it can crease although if they are small creases you can remove them by smoothing over by hand after you have reinstalled everything.
I did this months ago so hope I havn't missed anything, if you have any trouble PM me your mobile and I'll help any way I can. It is a really fiddly job and you will swear more than once ;-)