You have probably already searched the forum. This post may be useful: Weekend work - Pulling an IRS
I also suggest you consider the age and condition of the disks. To replace them, you would need to remove and replace the calipers. But it will never be easier to do.
Assuming you intend changing the trailing arm bushes and since you have an S2, you may be lucky and be able to easily remove the trailing arms from the IRS after it is off the car. Take a look at the spring mounts on the lower IRS arms. If you have a later S2, you may find that they are made so that you can easily disconnect the lower end of the springs, and then remove a round piece that in turn will allow clearance access to the transverse, rear bolt of the trailing arm. On the S1, this was not possible and removing the trailing arm required more disassembly.