Update on the '08 Astra

So... I didn't get the job done today as I had hoped to. There are a number of reasons why, but the main thing was that the exhaust manifold (which is one piece with the front catalytic converter) simply did not want to come out of the engine bay. It refused. Let me paste the steps of my plan that I actually got through today (9 our of 30) here and make some comments on each.
  1. Disconnect negative terminal on battery
    Obviously, the easiest part of this job.

  2. Drain coolant --not all coolant will drain from block, so some will leak from tubes when disconnected from block
    I decided not to do this because when I pull the coolant pipes out, coolant will drain from the block. I'll just put a catch pan under the car. I suppose I could pull the bottom hose off of the radiator; I might still do that.

  3. Disconnect O2 sensor plug
    I actually ended up removing sensor altogether because when I started trying to remove the manifold and catalytic converter, I didn't want it catching on anything and breaking.

  4. Remove heat shield
    Here is where I actually began to have trouble. Let me just say that if you watch YouTube videos of this job, you need to realize that things in your car's engine bay will be A LOT tighter than they look on people's videos. It took me a while to get that flimsy little shield out of there, and I am glad it is flimsy and somewhat flexible, because I needed to contort it a little in order to free it. PLEASE NOTE, if you're doing this on an Astra and it has A/C, you're going to have trouble unless you add a few steps, which I did. Keep reading.

  5. Remove oil dipstick tube (oil pan underneath!!) and place rag in the dipstick hole to keep debris out
    This was also easy. Also, the pan underneath was not necessary.

  6. Disconnect exhaust pipe at bottom of catalytic converter
    Easy peasy. I was actually surprised how easily the fasteners came off. I did spray them with a bit of penetrating oil, but I am not sure that I needed to. They turned right away.

  7. Disconnect retainer bolts/nuts (from underneath) from midway up catalytic converter
    This wasn't too difficult except that access to the fasteners was tight.

  8. Remove exhaust manifold retainer nuts
    Again, I was surprised at how easily these nine nuts came loose and came off. Like the exhaust flange beneath the car, I sprayed way with a bit of penetrating oil. However, I may not have needed to.

  9. Remove exhaust manifold and front catalytic converter (topside) and set aside
    Ok friends. This part was a nightmare. There was absolutely no way that the manifold/front cat was coming out of that space. It got caught on everything. In fact, at one point I almost got it out but I wedged it in so tight that I almost couldn't even push it back into its place! Here's the deal: if you have A/C in your Astra and you are doing this job, you have a few options:. First, you could try to bend your A/C pipes to make it work. This is highly inadvisable because if you break one of those lines, you will be up a creek without a paddle for a number of reasons, not least of which is that you will release all of your refrigerant into the air and likely right into your face. That would not be cool (no pun intended). Second, you could disconnect your A/C lines rather than bend them. However, if you don't have the machine to remove the refrigerant from the system before you do so, you'll end up in the same place as the first option. Third, you can remove the cooling fan from the radiator. This is what I ended up doing and it worked PERFECTLY. I cannot for the life of me figure out why none of the videos didn't suggest doing this! But there is a relatively minor drawback here, too. There is part of the airbox that fits on top of the radiator and under the top part of the front clip. It has to come out for the fan to come out. That means that you have to remove the grille (well, I did but it might not have been necessary), remove three fasteners from the top of the front clip (where the hood latch lives), pull up on that piece, and squeeze that little plastic jug looking thing out of there. Oh, I forgot, that plastic thing has its own fasteners to be undone first, of course. Once that was out, I crawled under the car, unplugged the fan wires on one corner and disconnected them from the plastic clip holding them to the fan shroud. Then I slid to the other corner and released the A/C wires that were fastened to the fan shroud. NOTE: those little plastic "Christmas tree" fasteners are a royal pain in the tuchus. Then it was a matter of unscrewing a torx bolt from the top corners and carefully lifting it up and out, maneuvering it just right so as not to catch any radiator hoses. Once that was out, the manifold + cat unit lifted right out with absolutely no problem! I had all the clearance I needed and then some.
Well, that is as far as I got today, I am embarrassed to say. I did, however, win a battle today. Tomorrow I hope to win the war by completing the remaining steps.
Grille Removed
Fan out (right) led to victory over the exhaust manifold + cat
The remainder of the job (i.e., the actual job I am trying to do) should be done tomorrow (barring any other freakish snags)