A few people asked about being able to remove the exhaust without taking off the side sills. As I said, the Corsa was already on the car when I purchased it. I had it off a few times since then to do other work because it was in the way. Any clamps and brackets that I had to loosen were easy to get to from underneath. The stock resonator was already off.
I guess the confusion comes from the fact that the Corsa system includes resonators that replace the OEM resonators just behind the cats inside the sills, and then it also includes the mufflers at the rear. The clamps just outside the sill are between the resonator and muffler on my Corsa system. So, I'm guessing that either you thought that the part outside the sills was all there is to the Corsa system; or, the previous owner had decided to use a straight pipe instead of the OEM or Corsa resonator in the sill, so, on your car, what is accessible is all there really is from Corsa.
I just wanted to make sure that the OP wasn't inadvertently mislead into thinking he didn't have to remove the sills in order to install the full system. (It was a bit of a hassle to reinstall them on my car.)