Ok, so a while back i needed to get to my com 2000 unit on my 57 reg Berlingo. I managed to find a site which had step by step instructions, so i will use their pictures here, and write my own description from experience. Recognition to the original author can be found at the bottom.
This took me around 1hr 30, and i reckon i could do it quicker now that i know how to remove that damned airbag!
Ok, so this is what we are trying to get to.
Torx T20 to remove the interior trim (Torx is a star type, tamper proof bolt).
Torx T50 to remove steering wheel
Short flat blade screw driver ( 2 of them could be beneficial)
10mm socket + extension + ratchet
Torch or very good sunlight to rear of steering wheel.
Citroen Manual Wrote:Edit: Supplied by UFO regarding airbag:
>Disconnect the battery for at least 30 minutes before commencing work - and do not use one of those code saver devices for saving radio settings.
>After the airbag is removed it should not be stored inside the car. Preferably in a strong cupboard or box away from your general work area. Static electricity should also be avoided.
I left it disconnected for 40 mins to be safe. Please make sure you do this step, it is not a joke.
Undo the 3X T20 screws under the steering column & remove the upper & lower trim pieces.
Then put key in the ignition & turn steering wheel to about 9o'clock.
Gently prise out the rear cover of the steering wheel so it sits free of the wheel (as free as it can be. It's squashy).
Now the hard part, removing the airbag. Get behind your steering wheel, and pull back the soft plastic cover that is at the back of the steering wheel.
Flex this rear cover at about the same area as the rectangular cut outs on the cover & look inside for some galvanised fencing wire looking stuff clipped over a bracket. There is one close to the column & another on the outer part. Unclip the outer one & pull on the airbag to ensure it's free on that corner.
Turn the steering wheel the other side (3o'clock) & do the same maneuver ensuring you don't pop the other side back in.
With the sides undone you now need to turn the steering wheel upside down (bottom to top) & fold back the flexible material on the steering wheel itself to view the last clip.
Here is a picture of this galvanised fencing wire you are trying to remove. It is removed by getting in between the plastic cover and the back of the steering wheel, and 'unhooking' it from where it is latched.
Another picture to try and help you.
The airbag should now be free.
There is one earth wire & one connector to disconnect.
Undoing the connections requires the blade screwdriver to prise the plastic strap off at the connection end & simply pulling it off. There is another connection pushed into a compartment in the steering wheel & another earth wire spade connector.
We are now ready to remove the steering wheel.
I set the front road wheels to the straight ahead position & steering wheel to exactly straight. Remove the keys .
Undo the Torx T50 bolt (not overly tight I found) & by using the arrow printed on the steering wheel, mark the spline position using a black pen. (or like a think felt pen)
Pull the steering wheel off carefully feeding the connectors through the access hole.
To remove the com2000 unit, you need to undo the 10mm bolt on the strap from underneath. There is a tab on the top & bottom of steering column you need to lift to allow the unit to move forward & off the column. Undo the connections (colour coded) & throw old com2000 away (if you want to).
Now putting everything back...
Ensure you line up the spline on the steering wheel.
Make sure the airbag holding wire is back in place all clipped where it should be. The black & red wires have plastic guides. Make sure they go back into them. There is one plug not used on the Berlingo behind the airbag.
Airbag is simply pushed back onto the steering wheel. You should hear it clip in.
. Thanks to http://www.aussiefrogs.com
for the pictures and some of the text content. I did follow this myself and i have learnt a lot from it. Saved me taking it to a mechanic. If i can do it, you can too.