This guide for replacing brake disks and pads was kindly provided by “Fatman” at diagnostics.org.uk.
Whilst applicable to the Astra H and Zafira, the same principles may apply to other models.
Remove the engine plastic cover
Locate the EGR Valve
Undo the bolts shown. Watch out for the two metal gaskets.
It can get very clogged up to the point of becoming blocked
Don′t forget to check the engine side as well
With the callipers now off if you are changing the disc you will need to turn the disc so this little screw is at the top. But i would remove the discs anyway.
Once this is removed the calliper and disc can be removed, the disk may take a few taps with a hammer.
Remove the pads
With the pads open take of this clip, then knock it out. Mine was a bit stiff so i used some gentle persuasion
The Piston needs to be pushed back in. Put the new pads in. Put the one that goes into the piston on first, i put a bit of copper grease over the back of the pad and at each corner. Then put the other in but dont for get to peel off the backing if there is one.
Fit the discs and put the retaining screw back in.