Today i changed my top mounts on the S3, i didnt take photos its not really that difficult to be honest.
1. Loosen the wheel bolts.
2. Get the front up on axle stands.
3. Remove both wheels.
4. Release the xeon level sensor found on the passenger side.
5. Remove the nut from the lower drop link connecting to the ARB.
6. Using the correct sized allen key & spark plug socket undo the strut cap bolts (the piston will just turn if you dont lock it in place with the allen key).
7. Compress the springs by 1-2inches.
8. Undo the inner bearing nut with the piston locked to remove the bearings, the spring strut cap should now be loose.
9. Install the bearing ensuring the spring strut cap is flush (you may need to compress the springs some more).
10. Jack the wish bone up to allow instalation of the inner bearing nut again locking the piston.
11. Release / lower the wishbone.
12. From inside the arch you should be able to push the strut to one side to allow the top mount to slip over the top.
13. Remove the spring compressors ensuring the spring is seated correctly.
14. Jack the wish bone up again so the mount sits firmly inside the strut top.
15. Install the strut cap nut again locking the piston.
16. Adjust the jack to align lower drop link with ARB & install the nut.
17. Secure the xneon level sensor.
18. Wheels back on, remove jack stands & tighten bolts.
Its quite easy to allow the pistion to sink into the shock if you have this problem you need to jack the wish bone up install the nut & using a C spanner to lever the piston out as far as possible, its worth checking this before you re-assemble as there wont be enough exposed thread on the piston to install the top cap.