[Philster]

remove the undertray under the driver's side - half a dozen 12mm bolts - you should be able to see it from there.

You can do it without a jack, but it may be easier to get it up in the air for more working space. If you do, use stands after jacking it, or good strong ramps (you don't want an esti on your head, they are nearer two tons than one).

You only need to change the actuator, which is the little can on the end of the cranked rod (will be clearer once you're under there).

I think there's a full tutorial in the member's area.