Well I did it.
I removed the heatshield next to the unit first in order to have better access to the lower hose clamps.
Emptied out the reservoir with a big plastic syringe, off with the lock nut and out with plastic piece and the spring underneath.
Needlenose pliers for the filter.
Then first hoseclamp at reservoir side with Philipshead screwdriver.
The lower part is easier reached with a little ratchet.
Once you pull it off, oil drains out ...
Then the bottom hoseclamp and the hose can be pulled off the tubing there as well. More oil ...
Finally a 22 mm wrench at the nut at the steering pump and out comes the tubing with hose attached. Very little oil left at that end.
I removed the tubing into the reservoir too to make assembly easier.
If you look at the last photo, you will see that the hose butts against a "knuckle". There a two knuckles at each tubing end and for whatever reason the hose was only slid over one of them.
I thought it would be better to slide it over both nuckles with the hoseclamp in between.
So I cut the hoses a little longer to allow for that extra 1/2 inch.
The one at the reservoir turned out to be too long as the hose had to bend too much and the sharper radius narrowed the diameter somewhat. So off again and shortened.
Now I made a mistake by installing the new filter, spring etc. into the reservoir housing. I had forgotten about the flushing I wanted to do. I spare you the details but flushing should be done probably without the filter in and with the return opening solidly plugged (a bolt?). The return line should be solidly in a container with a small opening like a milk container. Just that a milk container is too big for the space available.
As I had predicted earlier, oil everywhere. It took a roll of papertowel to clean it all up. The flush was aborted.....
There is one other thing that I would like to share. The original MB hoseclamps were not available at the local dealer and he sold me regular clamps. But the MB clamps are better as they surround the hose with a solid metal sheet and the thread of the tightener doesn't touch the rubber. I'll attach one picture where you can see some "weeping" at one clamp. The others seem all ok. I am not sure whether I got some oil on the clamp first or wether the thread cut into the rubber. I'll keep an eye on it the next days. I'll attach a second picture to show how much more I slid the hose over the tubing compared to the original setup.
I took some more pictures, but I am not sure whether it is worth to attach them.
If someone is interested, I can e-mail them off list.
I hope my description will help someone in the future.