Register at www.citroenchat.com, and download the file attached to "http://www.citroenchat.com/forum/index.php?PHPSESSID=0c64023c134d9d27e995a4f0731bfc7c&topic=603.0"
You will find a how to with pictures, but a warning in advance, its very difficult and should be left to a proper mechanic
Fellow C5
October 2008
If you are having to ask this question then I guess your not technically able to do it either, therefore I suggect you leave it to a proper mechanic as you may do more harm than good.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.