At first this looked like an impossible task and I read elsewhere on varoius forums that this would have to be done by a dealer because of the 'stupid design'.
However once you screw the back off the head lamp unit, use a small mirror and you will see that there is a spring clip holding the bulb to the head lamp unit and a connector that is attached to the bulb.
Pull the connector off.
Push the spring clip to the left or right (depending on the side you are changing) so that it unhooks. The spring clip should release fairly easily.
Pull out the bulb and that's it. The job can be done in less than five minutes.
Tandy, October 2010