Sorry if this is a bit late - they are talking complete ********.
There's a good guide on the web site that was done some years ago. It is a tricky job but not beyond anyone with some patience. If you buy a cable try to obtain the one with the modified end(not the hook, the bloody hook) or, if you have the inclination modify the new one.
And No the parcel shelf does not come out.
remove the pasenger seat and the ECU behind the carpet, carefully, and you can gain access fairly easily to the linkage, quadrant and cable. Do not over adjust; this is what tends to break them in the first place. When set correctly the action should be smooth with a slight decrease in pressure approx 2/3 travel distance to the floor.