just replaced them on my astra coupe ( basically the same as zafira ). im no mechanic but found these very straight forward. just jack up the car , take off the wheel & undo the bolts on the drop links . as well as a socket set you will need another spanner for the rear of the nuts, think its a 19mm . the only advice i would give is lube all the nuts n bolts with wd40 a couple of days b4 to free them off & also a spare jack will come in handy to jack up the suspension (placed under the bottom arm) to ease removal of the drop links .
Glynn, June 2009