Hey folks, I realise that I should have taken pictures, but to be honest, I was more focused on getting the job done and worrying if it would work or not
Step 1 - You need to source a DAB Antenna, I bought mine from a seller on eBay here, he was very very helpful so I would recommend buying from him rather than Kufatec;
http://www.ebay.co.uk/itm/281240384275?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649You can if you wanted also buy them from Kufatec here;
http://www.kufatec.de/shop/de/Nachruestset-DAB-/-DAB-AntennenmodulStep 2 - Open the boot, at the top of the windscreen you need to pull off the trim, this is difficult but use a bit of force as it is clipped in, use trim tools if you have any or brute force may well work! I didn't pull the entire trim off, I just pulled enough to see the antenna and worked on it like that, not ideal, but saves having to re-align the trim once removed fully!
Step 3 - You will see 2 Antennas one on the left and one on the right (as you are looking in at the boot) they are marked with a part code and also have 'L' and 'R' on them.
You need to change the one that has 'L' on it, the part on mine was 5K0.035.552.A To do this, unclip the brown fakra connector, then on the opposite side there will be a bit of black tape, remove this to expose a small black connector cable, gently unclip this also, and you will see a screw holding the antenna in, unscrew this and the antenna should slide out.
Step 4 - Now you will notice on your new antenna it has 2 FAKRA connection inputs, the eBay seller I used, also gives you a double connector adaptor, this is what you need, so if you order from Kufatec you may not get that, so be aware that you need one of those if not.
The brown fakra connector you took off from the original antenna, you need to unclip it from it's housing, simply lift up the purple clip fully with a flat head screwdriver, and the cable will then pull away from it's housing.
You then need to do the same with one side of the new aerial cable that you received in the packaging with the new DAB Antenna, so you are then left with 2 cables without Fakra connectors on, the double connector adapter has '1' and '2' on them, I used the existing cable in '2' and the new DAB cable wiring in '1' (unclip the purple clip from the double connector and slide your existing FM Cable into one hole, and the new DAB cable wire into the other hole) replace the purple clip and they should be snugly inside the double connector - make sure you push them in fully.
Also, remove the FAKRA connector from the other side of the DAB wire (this is the wire that goes into the car) as you need to feed that wire into the car and will have no chance of doing that if the connector is on the end of it!
Step 5 -OK, now, the new antenna had a different mount to the existing, so I actually just used some strong tape to hold it in place while I figure a new solution (if I bother as it works fine as it is) but anyhow, your next step is to feed the wire from the DAB antenna into the car, you will see to the top right of the bootlid a ribbed rubber grommet, pull it out from the top and also pull it out from where it connects into the car, now this is quite a thin grommet inside, so you will be unable to fit the wire inside it without a bit of butchering.
I used a blade to cut open the grommet and slide the wire inside, then taped over the sliced rubber, this is not ideal, but once again, I will be buying a bigger replacement grommet or something similar to use to replace this when I can.
Step 6 - Sit in the driver side rear seat, and look behind you, you will see 'AIRBAG' on a badge behind the rear headrest to the rear driver side of the car, unclip this gently with a trim tool, and it will expose a screw, unscrew that, and gently pull away at the trim, it will lever enough of a gap for you to feed the aerial wire from the boot into the car, from then, start pulling the wire through gently until all you need is through, then replace the trim, tighten the screw behind the AIRBAG badge, then put the badge back.
At this point, you are left with a lot of aerial cable dangling from the roof
Step 7 - Simply pull away gently at the headlining, and route the cable towards the A-Pillar on the drivers side of the car, use the outside of it to route (just under the rubber seal) so that it does not go near the airbags, there is enough of a gap for the cable to sink inside it and sit snug.
Once you get to the A-Pillar, again, route it down the outside, no need to remove the A-Pillar, head toward the fusebox area, pull off the fuse box door, and route the cable inside there (if you ever fitted a Bluetooth mic, you will be familiar with this part).
There is a storage box/drawer underneath the driver steering wheel, pull the handle so it opens, then squeeze the inside parts gently and pull it down so it comes down a little further, then simply pull it towards you, and that drawer will come out fully.
From there, nice and easy, feed the cable through towards the stereo.
Step 8 - Remove the Radio - this is nice and quick, simply pry the trim around the stereo with a trim tool and pull it off gently, exposing 4 screws that hold the Radio in place, unscrew those, and then pull the radio out towards you, I didn't bother undoing any of the cables, as I am lazy like that, so just put a cloth or piece of bubble wrap on the gearknob, and let the radio rest on that.
Use your right hand to feed the wire from underneath the steering area and your left hand put inside the gap where the radio was, and you should be able to make your hands meet
pull the cable through including all excess cable, as you don't want that sagging anywhere, wind the excess cable gently and use some electrical tape or clips to keep the wire together.
Step 9 - Remember you took the FAKRA connector off this cable to help route it through the car? Well go back and get it as you need it now! Simply push the cable end into the FAKRA connector and replace the purple clip, nice and snug, then plug it into your DAB socket on your radio.
Slide the radio back gently, making sure you do not trap any wires, tighten the screws to keep the radio in place, and then put the fascia back.
Step 10 - Turn on your radio, press to get into the DAB screen, and then click 'SCAN'
Enjoy the delights of DAB radio!
Once again, I know this would have been better with pics, but I hope this helps anyone who wants to do this retrofit, it's honestly not a daunting task, and took me around 45 minutes to do.