I've just fitted front pads to my 2001 Astra 1.6 hatchback. Quite easy, took about an hour but could probably have done it faster if I wanted to. Make sure car is on a flat before jacking up, handbrake is on, gears in neutral, and chock the rear wheels if you can. Jack it up and remove one wheel. There are two bolts accessed from the inside side of the brake caliper. You need a TORX bit (size T45) to loosen these. Loosen them till they are out of the threaded holes, or completely remove them if you want. There is a big spring clip, attached to the outer pad, holding it to the caliper. Unclip this. This might be a good time to depress the brake piston. I carefully used a screwdriver between the old pad and the caliper to do this - although you do have to be carefull as excess force could damage the disc. Then a bit of a wiggle up and forward on the caliper and it should come free. Remove the old pads. Install the new pads but watch the orientation. These things are 'handed' by a small spring clip attached to them. The clip should be to the top. They will fit in the caliper any way round but the caliper won't go back in place unless they are right. If you can't fit the caliper and pads back onto the disc, then you may need to depress the brake cylinder into the caliper a bit more. It should go back on quite easily in the reverse of removal. Remember to put the big spring clips (attached to the pads) over the caliper. Remember to re-install the two bolts. Maybe press your brake pedal a few times just now to make sure the brake piston is working and the pads contact the disc. Put your wheel on and lower the jack. Now do the same on the other side.
Johnoink, November 2006